Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

187 files changed, 6641 insertions, 0 deletions

diff --git a/intl/icu_capi/c/include/CodePointRangeIterator.h b/intl/icu_capi/c/include/CodePointRangeIterator.h
new file mode 100644
index 0000000000..36d6d23175
--- /dev/null
+++ b/intl/icu_capi/c/include/CodePointRangeIterator.h
@@ -0,0 +1,30 @@
+#ifndef CodePointRangeIterator_H
+#define CodePointRangeIterator_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct CodePointRangeIterator CodePointRangeIterator;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "CodePointRangeIteratorResult.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+CodePointRangeIteratorResult CodePointRangeIterator_next(CodePointRangeIterator* self);
+void CodePointRangeIterator_destroy(CodePointRangeIterator* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/CodePointRangeIteratorResult.h b/intl/icu_capi/c/include/CodePointRangeIteratorResult.h
new file mode 100644
index 0000000000..846873be11
--- /dev/null
+++ b/intl/icu_capi/c/include/CodePointRangeIteratorResult.h
@@ -0,0 +1,32 @@
+#ifndef CodePointRangeIteratorResult_H
+#define CodePointRangeIteratorResult_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct CodePointRangeIteratorResult {
+    uint32_t start;
+    uint32_t end;
+    bool done;
+} CodePointRangeIteratorResult;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void CodePointRangeIteratorResult_destroy(CodePointRangeIteratorResult* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XAnyCalendarKind.h b/intl/icu_capi/c/include/ICU4XAnyCalendarKind.h
new file mode 100644
index 0000000000..329f381577
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XAnyCalendarKind.h
@@ -0,0 +1,55 @@
+#ifndef ICU4XAnyCalendarKind_H
+#define ICU4XAnyCalendarKind_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XAnyCalendarKind {
+  ICU4XAnyCalendarKind_Iso = 0,
+  ICU4XAnyCalendarKind_Gregorian = 1,
+  ICU4XAnyCalendarKind_Buddhist = 2,
+  ICU4XAnyCalendarKind_Japanese = 3,
+  ICU4XAnyCalendarKind_JapaneseExtended = 4,
+  ICU4XAnyCalendarKind_Ethiopian = 5,
+  ICU4XAnyCalendarKind_EthiopianAmeteAlem = 6,
+  ICU4XAnyCalendarKind_Indian = 7,
+  ICU4XAnyCalendarKind_Coptic = 8,
+  ICU4XAnyCalendarKind_Dangi = 9,
+  ICU4XAnyCalendarKind_Chinese = 10,
+  ICU4XAnyCalendarKind_Hebrew = 11,
+  ICU4XAnyCalendarKind_IslamicCivil = 12,
+  ICU4XAnyCalendarKind_IslamicObservational = 13,
+  ICU4XAnyCalendarKind_IslamicTabular = 14,
+  ICU4XAnyCalendarKind_IslamicUmmAlQura = 15,
+  ICU4XAnyCalendarKind_Persian = 16,
+  ICU4XAnyCalendarKind_Roc = 17,
+} ICU4XAnyCalendarKind;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLocale.h"
+#include "diplomat_result_ICU4XAnyCalendarKind_void.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_ICU4XAnyCalendarKind_void ICU4XAnyCalendarKind_get_for_locale(const ICU4XLocale* locale);
+
+diplomat_result_ICU4XAnyCalendarKind_void ICU4XAnyCalendarKind_get_for_bcp47(const char* s_data, size_t s_len);
+
+diplomat_result_void_ICU4XError ICU4XAnyCalendarKind_bcp47(ICU4XAnyCalendarKind self, DiplomatWriteable* write);
+void ICU4XAnyCalendarKind_destroy(ICU4XAnyCalendarKind* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XBcp47ToIanaMapper.h b/intl/icu_capi/c/include/ICU4XBcp47ToIanaMapper.h
new file mode 100644
index 0000000000..483afe1ec2
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XBcp47ToIanaMapper.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XBcp47ToIanaMapper_H
+#define ICU4XBcp47ToIanaMapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XBcp47ToIanaMapper ICU4XBcp47ToIanaMapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError ICU4XBcp47ToIanaMapper_create(const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XBcp47ToIanaMapper_get(const ICU4XBcp47ToIanaMapper* self, const char* value_data, size_t value_len, DiplomatWriteable* write);
+void ICU4XBcp47ToIanaMapper_destroy(ICU4XBcp47ToIanaMapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XBidi.h b/intl/icu_capi/c/include/ICU4XBidi.h
new file mode 100644
index 0000000000..1ed7cfc8c2
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XBidi.h
@@ -0,0 +1,45 @@
+#ifndef ICU4XBidi_H
+#define ICU4XBidi_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XBidi ICU4XBidi;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XBidi_ICU4XError.h"
+#include "ICU4XBidiInfo.h"
+#include "ICU4XReorderedIndexMap.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XBidi_ICU4XError ICU4XBidi_create(const ICU4XDataProvider* provider);
+
+ICU4XBidiInfo* ICU4XBidi_for_text(const ICU4XBidi* self, const char* text_data, size_t text_len, uint8_t default_level);
+
+ICU4XReorderedIndexMap* ICU4XBidi_reorder_visual(const ICU4XBidi* self, const uint8_t* levels_data, size_t levels_len);
+
+bool ICU4XBidi_level_is_rtl(uint8_t level);
+
+bool ICU4XBidi_level_is_ltr(uint8_t level);
+
+uint8_t ICU4XBidi_level_rtl();
+
+uint8_t ICU4XBidi_level_ltr();
+void ICU4XBidi_destroy(ICU4XBidi* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XBidiDirection.h b/intl/icu_capi/c/include/ICU4XBidiDirection.h
new file mode 100644
index 0000000000..33de81d6e9
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XBidiDirection.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XBidiDirection_H
+#define ICU4XBidiDirection_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XBidiDirection {
+  ICU4XBidiDirection_Ltr = 0,
+  ICU4XBidiDirection_Rtl = 1,
+  ICU4XBidiDirection_Mixed = 2,
+} ICU4XBidiDirection;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XBidiDirection_destroy(ICU4XBidiDirection* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XBidiInfo.h b/intl/icu_capi/c/include/ICU4XBidiInfo.h
new file mode 100644
index 0000000000..02e8c21659
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XBidiInfo.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XBidiInfo_H
+#define ICU4XBidiInfo_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XBidiInfo ICU4XBidiInfo;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XBidiParagraph.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+size_t ICU4XBidiInfo_paragraph_count(const ICU4XBidiInfo* self);
+
+ICU4XBidiParagraph* ICU4XBidiInfo_paragraph_at(const ICU4XBidiInfo* self, size_t n);
+
+size_t ICU4XBidiInfo_size(const ICU4XBidiInfo* self);
+
+uint8_t ICU4XBidiInfo_level_at(const ICU4XBidiInfo* self, size_t pos);
+void ICU4XBidiInfo_destroy(ICU4XBidiInfo* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XBidiParagraph.h b/intl/icu_capi/c/include/ICU4XBidiParagraph.h
new file mode 100644
index 0000000000..269f940cc7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XBidiParagraph.h
@@ -0,0 +1,43 @@
+#ifndef ICU4XBidiParagraph_H
+#define ICU4XBidiParagraph_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XBidiParagraph ICU4XBidiParagraph;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XBidiDirection.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_void_ICU4XError ICU4XBidiParagraph_set_paragraph_in_text(ICU4XBidiParagraph* self, size_t n);
+
+ICU4XBidiDirection ICU4XBidiParagraph_direction(const ICU4XBidiParagraph* self);
+
+size_t ICU4XBidiParagraph_size(const ICU4XBidiParagraph* self);
+
+size_t ICU4XBidiParagraph_range_start(const ICU4XBidiParagraph* self);
+
+size_t ICU4XBidiParagraph_range_end(const ICU4XBidiParagraph* self);
+
+diplomat_result_void_ICU4XError ICU4XBidiParagraph_reorder_line(const ICU4XBidiParagraph* self, size_t range_start, size_t range_end, DiplomatWriteable* out);
+
+uint8_t ICU4XBidiParagraph_level_at(const ICU4XBidiParagraph* self, size_t pos);
+void ICU4XBidiParagraph_destroy(ICU4XBidiParagraph* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCalendar.h b/intl/icu_capi/c/include/ICU4XCalendar.h
new file mode 100644
index 0000000000..9ea6484b5f
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCalendar.h
@@ -0,0 +1,37 @@
+#ifndef ICU4XCalendar_H
+#define ICU4XCalendar_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCalendar ICU4XCalendar;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_box_ICU4XCalendar_ICU4XError.h"
+#include "ICU4XAnyCalendarKind.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCalendar_ICU4XError ICU4XCalendar_create_for_locale(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XCalendar_ICU4XError ICU4XCalendar_create_for_kind(const ICU4XDataProvider* provider, ICU4XAnyCalendarKind kind);
+
+ICU4XAnyCalendarKind ICU4XCalendar_kind(const ICU4XCalendar* self);
+void ICU4XCalendar_destroy(ICU4XCalendar* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCanonicalCombiningClassMap.h b/intl/icu_capi/c/include/ICU4XCanonicalCombiningClassMap.h
new file mode 100644
index 0000000000..f0fc447ba0
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCanonicalCombiningClassMap.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XCanonicalCombiningClassMap_H
+#define ICU4XCanonicalCombiningClassMap_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCanonicalCombiningClassMap ICU4XCanonicalCombiningClassMap;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError ICU4XCanonicalCombiningClassMap_create(const ICU4XDataProvider* provider);
+
+uint8_t ICU4XCanonicalCombiningClassMap_get(const ICU4XCanonicalCombiningClassMap* self, char32_t ch);
+
+uint8_t ICU4XCanonicalCombiningClassMap_get32(const ICU4XCanonicalCombiningClassMap* self, uint32_t ch);
+void ICU4XCanonicalCombiningClassMap_destroy(ICU4XCanonicalCombiningClassMap* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCanonicalComposition.h b/intl/icu_capi/c/include/ICU4XCanonicalComposition.h
new file mode 100644
index 0000000000..e9ae621739
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCanonicalComposition.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XCanonicalComposition_H
+#define ICU4XCanonicalComposition_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCanonicalComposition ICU4XCanonicalComposition;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCanonicalComposition_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCanonicalComposition_ICU4XError ICU4XCanonicalComposition_create(const ICU4XDataProvider* provider);
+
+char32_t ICU4XCanonicalComposition_compose(const ICU4XCanonicalComposition* self, char32_t starter, char32_t second);
+void ICU4XCanonicalComposition_destroy(ICU4XCanonicalComposition* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCanonicalDecomposition.h b/intl/icu_capi/c/include/ICU4XCanonicalDecomposition.h
new file mode 100644
index 0000000000..d18d108b90
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCanonicalDecomposition.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XCanonicalDecomposition_H
+#define ICU4XCanonicalDecomposition_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCanonicalDecomposition ICU4XCanonicalDecomposition;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError.h"
+#include "ICU4XDecomposed.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError ICU4XCanonicalDecomposition_create(const ICU4XDataProvider* provider);
+
+ICU4XDecomposed ICU4XCanonicalDecomposition_decompose(const ICU4XCanonicalDecomposition* self, char32_t c);
+void ICU4XCanonicalDecomposition_destroy(ICU4XCanonicalDecomposition* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCaseMapCloser.h b/intl/icu_capi/c/include/ICU4XCaseMapCloser.h
new file mode 100644
index 0000000000..ed2129006c
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCaseMapCloser.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XCaseMapCloser_H
+#define ICU4XCaseMapCloser_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCaseMapCloser ICU4XCaseMapCloser;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCaseMapCloser_ICU4XError.h"
+#include "ICU4XCodePointSetBuilder.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCaseMapCloser_ICU4XError ICU4XCaseMapCloser_create(const ICU4XDataProvider* provider);
+
+void ICU4XCaseMapCloser_add_case_closure_to(const ICU4XCaseMapCloser* self, char32_t c, ICU4XCodePointSetBuilder* builder);
+
+bool ICU4XCaseMapCloser_add_string_case_closure_to(const ICU4XCaseMapCloser* self, const char* s_data, size_t s_len, ICU4XCodePointSetBuilder* builder);
+void ICU4XCaseMapCloser_destroy(ICU4XCaseMapCloser* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCaseMapper.h b/intl/icu_capi/c/include/ICU4XCaseMapper.h
new file mode 100644
index 0000000000..aef264f722
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCaseMapper.h
@@ -0,0 +1,57 @@
+#ifndef ICU4XCaseMapper_H
+#define ICU4XCaseMapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCaseMapper ICU4XCaseMapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCaseMapper_ICU4XError.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XTitlecaseOptionsV1.h"
+#include "ICU4XCodePointSetBuilder.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCaseMapper_ICU4XError ICU4XCaseMapper_create(const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XCaseMapper_lowercase(const ICU4XCaseMapper* self, const char* s_data, size_t s_len, const ICU4XLocale* locale, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCaseMapper_uppercase(const ICU4XCaseMapper* self, const char* s_data, size_t s_len, const ICU4XLocale* locale, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCaseMapper_titlecase_segment_with_only_case_data_v1(const ICU4XCaseMapper* self, const char* s_data, size_t s_len, const ICU4XLocale* locale, ICU4XTitlecaseOptionsV1 options, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCaseMapper_fold(const ICU4XCaseMapper* self, const char* s_data, size_t s_len, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCaseMapper_fold_turkic(const ICU4XCaseMapper* self, const char* s_data, size_t s_len, DiplomatWriteable* write);
+
+void ICU4XCaseMapper_add_case_closure_to(const ICU4XCaseMapper* self, char32_t c, ICU4XCodePointSetBuilder* builder);
+
+char32_t ICU4XCaseMapper_simple_lowercase(const ICU4XCaseMapper* self, char32_t ch);
+
+char32_t ICU4XCaseMapper_simple_uppercase(const ICU4XCaseMapper* self, char32_t ch);
+
+char32_t ICU4XCaseMapper_simple_titlecase(const ICU4XCaseMapper* self, char32_t ch);
+
+char32_t ICU4XCaseMapper_simple_fold(const ICU4XCaseMapper* self, char32_t ch);
+
+char32_t ICU4XCaseMapper_simple_fold_turkic(const ICU4XCaseMapper* self, char32_t ch);
+void ICU4XCaseMapper_destroy(ICU4XCaseMapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCodePointMapData16.h b/intl/icu_capi/c/include/ICU4XCodePointMapData16.h
new file mode 100644
index 0000000000..19effe2d92
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCodePointMapData16.h
@@ -0,0 +1,43 @@
+#ifndef ICU4XCodePointMapData16_H
+#define ICU4XCodePointMapData16_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCodePointMapData16 ICU4XCodePointMapData16;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "CodePointRangeIterator.h"
+#include "ICU4XCodePointSetData.h"
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCodePointMapData16_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+uint16_t ICU4XCodePointMapData16_get(const ICU4XCodePointMapData16* self, char32_t cp);
+
+uint16_t ICU4XCodePointMapData16_get32(const ICU4XCodePointMapData16* self, uint32_t cp);
+
+CodePointRangeIterator* ICU4XCodePointMapData16_iter_ranges_for_value(const ICU4XCodePointMapData16* self, uint16_t value);
+
+CodePointRangeIterator* ICU4XCodePointMapData16_iter_ranges_for_value_complemented(const ICU4XCodePointMapData16* self, uint16_t value);
+
+ICU4XCodePointSetData* ICU4XCodePointMapData16_get_set_for_value(const ICU4XCodePointMapData16* self, uint16_t value);
+
+diplomat_result_box_ICU4XCodePointMapData16_ICU4XError ICU4XCodePointMapData16_load_script(const ICU4XDataProvider* provider);
+void ICU4XCodePointMapData16_destroy(ICU4XCodePointMapData16* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCodePointMapData8.h b/intl/icu_capi/c/include/ICU4XCodePointMapData8.h
new file mode 100644
index 0000000000..87fe8854b2
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCodePointMapData8.h
@@ -0,0 +1,61 @@
+#ifndef ICU4XCodePointMapData8_H
+#define ICU4XCodePointMapData8_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCodePointMapData8 ICU4XCodePointMapData8;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "CodePointRangeIterator.h"
+#include "ICU4XCodePointSetData.h"
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCodePointMapData8_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+uint8_t ICU4XCodePointMapData8_get(const ICU4XCodePointMapData8* self, char32_t cp);
+
+uint8_t ICU4XCodePointMapData8_get32(const ICU4XCodePointMapData8* self, uint32_t cp);
+
+uint32_t ICU4XCodePointMapData8_general_category_to_mask(uint8_t gc);
+
+CodePointRangeIterator* ICU4XCodePointMapData8_iter_ranges_for_value(const ICU4XCodePointMapData8* self, uint8_t value);
+
+CodePointRangeIterator* ICU4XCodePointMapData8_iter_ranges_for_value_complemented(const ICU4XCodePointMapData8* self, uint8_t value);
+
+CodePointRangeIterator* ICU4XCodePointMapData8_iter_ranges_for_mask(const ICU4XCodePointMapData8* self, uint32_t mask);
+
+ICU4XCodePointSetData* ICU4XCodePointMapData8_get_set_for_value(const ICU4XCodePointMapData8* self, uint8_t value);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_general_category(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_bidi_class(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_east_asian_width(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_indic_syllabic_category(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_line_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_try_grapheme_cluster_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_word_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointMapData8_ICU4XError ICU4XCodePointMapData8_load_sentence_break(const ICU4XDataProvider* provider);
+void ICU4XCodePointMapData8_destroy(ICU4XCodePointMapData8* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCodePointSetBuilder.h b/intl/icu_capi/c/include/ICU4XCodePointSetBuilder.h
new file mode 100644
index 0000000000..d36697c7cf
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCodePointSetBuilder.h
@@ -0,0 +1,64 @@
+#ifndef ICU4XCodePointSetBuilder_H
+#define ICU4XCodePointSetBuilder_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCodePointSetBuilder ICU4XCodePointSetBuilder;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XCodePointSetData.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XCodePointSetBuilder* ICU4XCodePointSetBuilder_create();
+
+ICU4XCodePointSetData* ICU4XCodePointSetBuilder_build(ICU4XCodePointSetBuilder* self);
+
+void ICU4XCodePointSetBuilder_complement(ICU4XCodePointSetBuilder* self);
+
+bool ICU4XCodePointSetBuilder_is_empty(const ICU4XCodePointSetBuilder* self);
+
+void ICU4XCodePointSetBuilder_add_char(ICU4XCodePointSetBuilder* self, char32_t ch);
+
+void ICU4XCodePointSetBuilder_add_u32(ICU4XCodePointSetBuilder* self, uint32_t ch);
+
+void ICU4XCodePointSetBuilder_add_inclusive_range(ICU4XCodePointSetBuilder* self, char32_t start, char32_t end);
+
+void ICU4XCodePointSetBuilder_add_inclusive_range_u32(ICU4XCodePointSetBuilder* self, uint32_t start, uint32_t end);
+
+void ICU4XCodePointSetBuilder_add_set(ICU4XCodePointSetBuilder* self, const ICU4XCodePointSetData* data);
+
+void ICU4XCodePointSetBuilder_remove_char(ICU4XCodePointSetBuilder* self, char32_t ch);
+
+void ICU4XCodePointSetBuilder_remove_inclusive_range(ICU4XCodePointSetBuilder* self, char32_t start, char32_t end);
+
+void ICU4XCodePointSetBuilder_remove_set(ICU4XCodePointSetBuilder* self, const ICU4XCodePointSetData* data);
+
+void ICU4XCodePointSetBuilder_retain_char(ICU4XCodePointSetBuilder* self, char32_t ch);
+
+void ICU4XCodePointSetBuilder_retain_inclusive_range(ICU4XCodePointSetBuilder* self, char32_t start, char32_t end);
+
+void ICU4XCodePointSetBuilder_retain_set(ICU4XCodePointSetBuilder* self, const ICU4XCodePointSetData* data);
+
+void ICU4XCodePointSetBuilder_complement_char(ICU4XCodePointSetBuilder* self, char32_t ch);
+
+void ICU4XCodePointSetBuilder_complement_inclusive_range(ICU4XCodePointSetBuilder* self, char32_t start, char32_t end);
+
+void ICU4XCodePointSetBuilder_complement_set(ICU4XCodePointSetBuilder* self, const ICU4XCodePointSetData* data);
+void ICU4XCodePointSetBuilder_destroy(ICU4XCodePointSetBuilder* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCodePointSetData.h b/intl/icu_capi/c/include/ICU4XCodePointSetData.h
new file mode 100644
index 0000000000..10356e90b7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCodePointSetData.h
@@ -0,0 +1,172 @@
+#ifndef ICU4XCodePointSetData_H
+#define ICU4XCodePointSetData_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCodePointSetData ICU4XCodePointSetData;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "CodePointRangeIterator.h"
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XCodePointSetData_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+bool ICU4XCodePointSetData_contains(const ICU4XCodePointSetData* self, char32_t cp);
+
+bool ICU4XCodePointSetData_contains32(const ICU4XCodePointSetData* self, uint32_t cp);
+
+CodePointRangeIterator* ICU4XCodePointSetData_iter_ranges(const ICU4XCodePointSetData* self);
+
+CodePointRangeIterator* ICU4XCodePointSetData_iter_ranges_complemented(const ICU4XCodePointSetData* self);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_for_general_category_group(const ICU4XDataProvider* provider, uint32_t group);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_ascii_hex_digit(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_alnum(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_alphabetic(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_bidi_control(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_bidi_mirrored(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_blank(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_cased(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_case_ignorable(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_full_composition_exclusion(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_casefolded(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_casemapped(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_nfkc_casefolded(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_lowercased(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_titlecased(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_changes_when_uppercased(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_dash(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_deprecated(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_default_ignorable_code_point(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_diacritic(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_emoji_modifier_base(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_emoji_component(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_emoji_modifier(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_emoji(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_emoji_presentation(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_extender(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_extended_pictographic(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_graph(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_grapheme_base(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_grapheme_extend(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_grapheme_link(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_hex_digit(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_hyphen(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_id_continue(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_ideographic(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_id_start(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_ids_binary_operator(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_ids_trinary_operator(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_join_control(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_logical_order_exception(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_lowercase(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_math(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_noncharacter_code_point(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_nfc_inert(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_nfd_inert(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_nfkc_inert(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_nfkd_inert(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_pattern_syntax(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_pattern_white_space(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_prepended_concatenation_mark(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_print(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_quotation_mark(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_radical(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_regional_indicator(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_soft_dotted(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_segment_starter(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_case_sensitive(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_sentence_terminal(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_terminal_punctuation(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_unified_ideograph(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_uppercase(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_variation_selector(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_white_space(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_xdigit(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_xid_continue(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_xid_start(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XCodePointSetData_ICU4XError ICU4XCodePointSetData_load_for_ecma262(const ICU4XDataProvider* provider, const char* property_name_data, size_t property_name_len);
+void ICU4XCodePointSetData_destroy(ICU4XCodePointSetData* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollator.h b/intl/icu_capi/c/include/ICU4XCollator.h
new file mode 100644
index 0000000000..973c2cedd9
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollator.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XCollator_H
+#define ICU4XCollator_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCollator ICU4XCollator;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XCollatorOptionsV1.h"
+#include "diplomat_result_box_ICU4XCollator_ICU4XError.h"
+#include "ICU4XOrdering.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCollator_ICU4XError ICU4XCollator_create_v1(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XCollatorOptionsV1 options);
+
+ICU4XOrdering ICU4XCollator_compare(const ICU4XCollator* self, const char* left_data, size_t left_len, const char* right_data, size_t right_len);
+
+ICU4XOrdering ICU4XCollator_compare_valid_utf8(const ICU4XCollator* self, const char* left_data, size_t left_len, const char* right_data, size_t right_len);
+
+ICU4XOrdering ICU4XCollator_compare_utf16(const ICU4XCollator* self, const uint16_t* left_data, size_t left_len, const uint16_t* right_data, size_t right_len);
+void ICU4XCollator_destroy(ICU4XCollator* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorAlternateHandling.h b/intl/icu_capi/c/include/ICU4XCollatorAlternateHandling.h
new file mode 100644
index 0000000000..dfc3d595eb
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorAlternateHandling.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XCollatorAlternateHandling_H
+#define ICU4XCollatorAlternateHandling_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorAlternateHandling {
+  ICU4XCollatorAlternateHandling_Auto = 0,
+  ICU4XCollatorAlternateHandling_NonIgnorable = 1,
+  ICU4XCollatorAlternateHandling_Shifted = 2,
+} ICU4XCollatorAlternateHandling;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorAlternateHandling_destroy(ICU4XCollatorAlternateHandling* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorBackwardSecondLevel.h b/intl/icu_capi/c/include/ICU4XCollatorBackwardSecondLevel.h
new file mode 100644
index 0000000000..659f9b2f10
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorBackwardSecondLevel.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XCollatorBackwardSecondLevel_H
+#define ICU4XCollatorBackwardSecondLevel_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorBackwardSecondLevel {
+  ICU4XCollatorBackwardSecondLevel_Auto = 0,
+  ICU4XCollatorBackwardSecondLevel_Off = 1,
+  ICU4XCollatorBackwardSecondLevel_On = 2,
+} ICU4XCollatorBackwardSecondLevel;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorBackwardSecondLevel_destroy(ICU4XCollatorBackwardSecondLevel* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorCaseFirst.h b/intl/icu_capi/c/include/ICU4XCollatorCaseFirst.h
new file mode 100644
index 0000000000..c01eb216d0
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorCaseFirst.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XCollatorCaseFirst_H
+#define ICU4XCollatorCaseFirst_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorCaseFirst {
+  ICU4XCollatorCaseFirst_Auto = 0,
+  ICU4XCollatorCaseFirst_Off = 1,
+  ICU4XCollatorCaseFirst_LowerFirst = 2,
+  ICU4XCollatorCaseFirst_UpperFirst = 3,
+} ICU4XCollatorCaseFirst;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorCaseFirst_destroy(ICU4XCollatorCaseFirst* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorCaseLevel.h b/intl/icu_capi/c/include/ICU4XCollatorCaseLevel.h
new file mode 100644
index 0000000000..cbf6865967
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorCaseLevel.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XCollatorCaseLevel_H
+#define ICU4XCollatorCaseLevel_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorCaseLevel {
+  ICU4XCollatorCaseLevel_Auto = 0,
+  ICU4XCollatorCaseLevel_Off = 1,
+  ICU4XCollatorCaseLevel_On = 2,
+} ICU4XCollatorCaseLevel;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorCaseLevel_destroy(ICU4XCollatorCaseLevel* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorMaxVariable.h b/intl/icu_capi/c/include/ICU4XCollatorMaxVariable.h
new file mode 100644
index 0000000000..0e5a3a516f
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorMaxVariable.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XCollatorMaxVariable_H
+#define ICU4XCollatorMaxVariable_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorMaxVariable {
+  ICU4XCollatorMaxVariable_Auto = 0,
+  ICU4XCollatorMaxVariable_Space = 1,
+  ICU4XCollatorMaxVariable_Punctuation = 2,
+  ICU4XCollatorMaxVariable_Symbol = 3,
+  ICU4XCollatorMaxVariable_Currency = 4,
+} ICU4XCollatorMaxVariable;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorMaxVariable_destroy(ICU4XCollatorMaxVariable* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorNumeric.h b/intl/icu_capi/c/include/ICU4XCollatorNumeric.h
new file mode 100644
index 0000000000..4dd2ec0408
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorNumeric.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XCollatorNumeric_H
+#define ICU4XCollatorNumeric_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorNumeric {
+  ICU4XCollatorNumeric_Auto = 0,
+  ICU4XCollatorNumeric_Off = 1,
+  ICU4XCollatorNumeric_On = 2,
+} ICU4XCollatorNumeric;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorNumeric_destroy(ICU4XCollatorNumeric* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorOptionsV1.h b/intl/icu_capi/c/include/ICU4XCollatorOptionsV1.h
new file mode 100644
index 0000000000..dc73557efe
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorOptionsV1.h
@@ -0,0 +1,50 @@
+#ifndef ICU4XCollatorOptionsV1_H
+#define ICU4XCollatorOptionsV1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XCollatorStrength.h"
+#include "ICU4XCollatorAlternateHandling.h"
+#include "ICU4XCollatorCaseFirst.h"
+#include "ICU4XCollatorMaxVariable.h"
+#include "ICU4XCollatorCaseLevel.h"
+#include "ICU4XCollatorNumeric.h"
+#include "ICU4XCollatorBackwardSecondLevel.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCollatorOptionsV1 {
+    ICU4XCollatorStrength strength;
+    ICU4XCollatorAlternateHandling alternate_handling;
+    ICU4XCollatorCaseFirst case_first;
+    ICU4XCollatorMaxVariable max_variable;
+    ICU4XCollatorCaseLevel case_level;
+    ICU4XCollatorNumeric numeric;
+    ICU4XCollatorBackwardSecondLevel backward_second_level;
+} ICU4XCollatorOptionsV1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XCollatorStrength.h"
+#include "ICU4XCollatorAlternateHandling.h"
+#include "ICU4XCollatorCaseFirst.h"
+#include "ICU4XCollatorMaxVariable.h"
+#include "ICU4XCollatorCaseLevel.h"
+#include "ICU4XCollatorNumeric.h"
+#include "ICU4XCollatorBackwardSecondLevel.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorOptionsV1_destroy(ICU4XCollatorOptionsV1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCollatorStrength.h b/intl/icu_capi/c/include/ICU4XCollatorStrength.h
new file mode 100644
index 0000000000..f230214feb
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCollatorStrength.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XCollatorStrength_H
+#define ICU4XCollatorStrength_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XCollatorStrength {
+  ICU4XCollatorStrength_Auto = 0,
+  ICU4XCollatorStrength_Primary = 1,
+  ICU4XCollatorStrength_Secondary = 2,
+  ICU4XCollatorStrength_Tertiary = 3,
+  ICU4XCollatorStrength_Quaternary = 4,
+  ICU4XCollatorStrength_Identical = 5,
+} ICU4XCollatorStrength;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XCollatorStrength_destroy(ICU4XCollatorStrength* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XComposingNormalizer.h b/intl/icu_capi/c/include/ICU4XComposingNormalizer.h
new file mode 100644
index 0000000000..1798af0d8e
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XComposingNormalizer.h
@@ -0,0 +1,38 @@
+#ifndef ICU4XComposingNormalizer_H
+#define ICU4XComposingNormalizer_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XComposingNormalizer ICU4XComposingNormalizer;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XComposingNormalizer_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XComposingNormalizer_ICU4XError ICU4XComposingNormalizer_create_nfc(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XComposingNormalizer_ICU4XError ICU4XComposingNormalizer_create_nfkc(const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XComposingNormalizer_normalize(const ICU4XComposingNormalizer* self, const char* s_data, size_t s_len, DiplomatWriteable* write);
+
+bool ICU4XComposingNormalizer_is_normalized(const ICU4XComposingNormalizer* self, const char* s_data, size_t s_len);
+void ICU4XComposingNormalizer_destroy(ICU4XComposingNormalizer* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XCustomTimeZone.h b/intl/icu_capi/c/include/ICU4XCustomTimeZone.h
new file mode 100644
index 0000000000..422b7fa382
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XCustomTimeZone.h
@@ -0,0 +1,84 @@
+#ifndef ICU4XCustomTimeZone_H
+#define ICU4XCustomTimeZone_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XCustomTimeZone ICU4XCustomTimeZone;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XCustomTimeZone_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "diplomat_result_int32_t_ICU4XError.h"
+#include "diplomat_result_bool_ICU4XError.h"
+#include "ICU4XIanaToBcp47Mapper.h"
+#include "ICU4XMetazoneCalculator.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XCustomTimeZone_ICU4XError ICU4XCustomTimeZone_create_from_string(const char* s_data, size_t s_len);
+
+ICU4XCustomTimeZone* ICU4XCustomTimeZone_create_empty();
+
+ICU4XCustomTimeZone* ICU4XCustomTimeZone_create_utc();
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_try_set_gmt_offset_seconds(ICU4XCustomTimeZone* self, int32_t offset_seconds);
+
+void ICU4XCustomTimeZone_clear_gmt_offset(ICU4XCustomTimeZone* self);
+
+diplomat_result_int32_t_ICU4XError ICU4XCustomTimeZone_gmt_offset_seconds(const ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_is_gmt_offset_positive(const ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_is_gmt_offset_zero(const ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_gmt_offset_has_minutes(const ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_gmt_offset_has_seconds(const ICU4XCustomTimeZone* self);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_try_set_time_zone_id(ICU4XCustomTimeZone* self, const char* id_data, size_t id_len);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_try_set_iana_time_zone_id(ICU4XCustomTimeZone* self, const ICU4XIanaToBcp47Mapper* mapper, const char* id_data, size_t id_len);
+
+void ICU4XCustomTimeZone_clear_time_zone_id(ICU4XCustomTimeZone* self);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_time_zone_id(const ICU4XCustomTimeZone* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_try_set_metazone_id(ICU4XCustomTimeZone* self, const char* id_data, size_t id_len);
+
+void ICU4XCustomTimeZone_clear_metazone_id(ICU4XCustomTimeZone* self);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_metazone_id(const ICU4XCustomTimeZone* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_try_set_zone_variant(ICU4XCustomTimeZone* self, const char* id_data, size_t id_len);
+
+void ICU4XCustomTimeZone_clear_zone_variant(ICU4XCustomTimeZone* self);
+
+diplomat_result_void_ICU4XError ICU4XCustomTimeZone_zone_variant(const ICU4XCustomTimeZone* self, DiplomatWriteable* write);
+
+void ICU4XCustomTimeZone_set_standard_time(ICU4XCustomTimeZone* self);
+
+void ICU4XCustomTimeZone_set_daylight_time(ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_is_standard_time(const ICU4XCustomTimeZone* self);
+
+diplomat_result_bool_ICU4XError ICU4XCustomTimeZone_is_daylight_time(const ICU4XCustomTimeZone* self);
+
+void ICU4XCustomTimeZone_maybe_calculate_metazone(ICU4XCustomTimeZone* self, const ICU4XMetazoneCalculator* metazone_calculator, const ICU4XIsoDateTime* local_datetime);
+void ICU4XCustomTimeZone_destroy(ICU4XCustomTimeZone* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDataProvider.h b/intl/icu_capi/c/include/ICU4XDataProvider.h
new file mode 100644
index 0000000000..8d7700e224
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDataProvider.h
@@ -0,0 +1,48 @@
+#ifndef ICU4XDataProvider_H
+#define ICU4XDataProvider_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDataProvider ICU4XDataProvider;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XDataProvider_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XLocaleFallbacker.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XDataProvider* ICU4XDataProvider_create_compiled();
+
+diplomat_result_box_ICU4XDataProvider_ICU4XError ICU4XDataProvider_create_fs(const char* path_data, size_t path_len);
+
+ICU4XDataProvider* ICU4XDataProvider_create_test();
+
+diplomat_result_box_ICU4XDataProvider_ICU4XError ICU4XDataProvider_create_from_byte_slice(const uint8_t* blob_data, size_t blob_len);
+
+ICU4XDataProvider* ICU4XDataProvider_create_empty();
+
+diplomat_result_void_ICU4XError ICU4XDataProvider_fork_by_key(ICU4XDataProvider* self, ICU4XDataProvider* other);
+
+diplomat_result_void_ICU4XError ICU4XDataProvider_fork_by_locale(ICU4XDataProvider* self, ICU4XDataProvider* other);
+
+diplomat_result_void_ICU4XError ICU4XDataProvider_enable_locale_fallback(ICU4XDataProvider* self);
+
+diplomat_result_void_ICU4XError ICU4XDataProvider_enable_locale_fallback_with(ICU4XDataProvider* self, const ICU4XLocaleFallbacker* fallbacker);
+void ICU4XDataProvider_destroy(ICU4XDataProvider* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDataStruct.h b/intl/icu_capi/c/include/ICU4XDataStruct.h
new file mode 100644
index 0000000000..a07ff02fb8
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDataStruct.h
@@ -0,0 +1,30 @@
+#ifndef ICU4XDataStruct_H
+#define ICU4XDataStruct_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDataStruct ICU4XDataStruct;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XDataStruct_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDataStruct_ICU4XError ICU4XDataStruct_create_decimal_symbols_v1(const char* plus_sign_prefix_data, size_t plus_sign_prefix_len, const char* plus_sign_suffix_data, size_t plus_sign_suffix_len, const char* minus_sign_prefix_data, size_t minus_sign_prefix_len, const char* minus_sign_suffix_data, size_t minus_sign_suffix_len, const char* decimal_separator_data, size_t decimal_separator_len, const char* grouping_separator_data, size_t grouping_separator_len, uint8_t primary_group_size, uint8_t secondary_group_size, uint8_t min_group_size, const char32_t* digits_data, size_t digits_len);
+void ICU4XDataStruct_destroy(ICU4XDataStruct* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDate.h b/intl/icu_capi/c/include/ICU4XDate.h
new file mode 100644
index 0000000000..f5a0c06de6
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDate.h
@@ -0,0 +1,66 @@
+#ifndef ICU4XDate_H
+#define ICU4XDate_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDate ICU4XDate;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XCalendar.h"
+#include "diplomat_result_box_ICU4XDate_ICU4XError.h"
+#include "ICU4XIsoDate.h"
+#include "ICU4XIsoWeekday.h"
+#include "ICU4XWeekCalculator.h"
+#include "diplomat_result_ICU4XWeekOf_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDate_ICU4XError ICU4XDate_create_from_iso_in_calendar(int32_t year, uint8_t month, uint8_t day, const ICU4XCalendar* calendar);
+
+diplomat_result_box_ICU4XDate_ICU4XError ICU4XDate_create_from_codes_in_calendar(const char* era_code_data, size_t era_code_len, int32_t year, const char* month_code_data, size_t month_code_len, uint8_t day, const ICU4XCalendar* calendar);
+
+ICU4XDate* ICU4XDate_to_calendar(const ICU4XDate* self, const ICU4XCalendar* calendar);
+
+ICU4XIsoDate* ICU4XDate_to_iso(const ICU4XDate* self);
+
+uint32_t ICU4XDate_day_of_month(const ICU4XDate* self);
+
+ICU4XIsoWeekday ICU4XDate_day_of_week(const ICU4XDate* self);
+
+uint32_t ICU4XDate_week_of_month(const ICU4XDate* self, ICU4XIsoWeekday first_weekday);
+
+diplomat_result_ICU4XWeekOf_ICU4XError ICU4XDate_week_of_year(const ICU4XDate* self, const ICU4XWeekCalculator* calculator);
+
+uint32_t ICU4XDate_ordinal_month(const ICU4XDate* self);
+
+diplomat_result_void_ICU4XError ICU4XDate_month_code(const ICU4XDate* self, DiplomatWriteable* write);
+
+int32_t ICU4XDate_year_in_era(const ICU4XDate* self);
+
+diplomat_result_void_ICU4XError ICU4XDate_era(const ICU4XDate* self, DiplomatWriteable* write);
+
+uint8_t ICU4XDate_months_in_year(const ICU4XDate* self);
+
+uint8_t ICU4XDate_days_in_month(const ICU4XDate* self);
+
+uint16_t ICU4XDate_days_in_year(const ICU4XDate* self);
+
+ICU4XCalendar* ICU4XDate_calendar(const ICU4XDate* self);
+void ICU4XDate_destroy(ICU4XDate* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDateFormatter.h b/intl/icu_capi/c/include/ICU4XDateFormatter.h
new file mode 100644
index 0000000000..8dc5316e47
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDateFormatter.h
@@ -0,0 +1,46 @@
+#ifndef ICU4XDateFormatter_H
+#define ICU4XDateFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDateFormatter ICU4XDateFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "diplomat_result_box_ICU4XDateFormatter_ICU4XError.h"
+#include "ICU4XDate.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XIsoDate.h"
+#include "ICU4XDateTime.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDateFormatter_ICU4XError ICU4XDateFormatter_create_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length);
+
+diplomat_result_void_ICU4XError ICU4XDateFormatter_format_date(const ICU4XDateFormatter* self, const ICU4XDate* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XDateFormatter_format_iso_date(const ICU4XDateFormatter* self, const ICU4XIsoDate* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XDateFormatter_format_datetime(const ICU4XDateFormatter* self, const ICU4XDateTime* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XDateFormatter_format_iso_datetime(const ICU4XDateFormatter* self, const ICU4XIsoDateTime* value, DiplomatWriteable* write);
+void ICU4XDateFormatter_destroy(ICU4XDateFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDateLength.h b/intl/icu_capi/c/include/ICU4XDateLength.h
new file mode 100644
index 0000000000..b2ca918233
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDateLength.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XDateLength_H
+#define ICU4XDateLength_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XDateLength {
+  ICU4XDateLength_Full = 0,
+  ICU4XDateLength_Long = 1,
+  ICU4XDateLength_Medium = 2,
+  ICU4XDateLength_Short = 3,
+} ICU4XDateLength;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XDateLength_destroy(ICU4XDateLength* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDateTime.h b/intl/icu_capi/c/include/ICU4XDateTime.h
new file mode 100644
index 0000000000..adb0a19798
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDateTime.h
@@ -0,0 +1,82 @@
+#ifndef ICU4XDateTime_H
+#define ICU4XDateTime_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDateTime ICU4XDateTime;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XCalendar.h"
+#include "diplomat_result_box_ICU4XDateTime_ICU4XError.h"
+#include "ICU4XDate.h"
+#include "ICU4XTime.h"
+#include "ICU4XIsoDateTime.h"
+#include "ICU4XIsoWeekday.h"
+#include "ICU4XWeekCalculator.h"
+#include "diplomat_result_ICU4XWeekOf_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDateTime_ICU4XError ICU4XDateTime_create_from_iso_in_calendar(int32_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second, uint32_t nanosecond, const ICU4XCalendar* calendar);
+
+diplomat_result_box_ICU4XDateTime_ICU4XError ICU4XDateTime_create_from_codes_in_calendar(const char* era_code_data, size_t era_code_len, int32_t year, const char* month_code_data, size_t month_code_len, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second, uint32_t nanosecond, const ICU4XCalendar* calendar);
+
+ICU4XDateTime* ICU4XDateTime_create_from_date_and_time(const ICU4XDate* date, const ICU4XTime* time);
+
+ICU4XDate* ICU4XDateTime_date(const ICU4XDateTime* self);
+
+ICU4XTime* ICU4XDateTime_time(const ICU4XDateTime* self);
+
+ICU4XIsoDateTime* ICU4XDateTime_to_iso(const ICU4XDateTime* self);
+
+ICU4XDateTime* ICU4XDateTime_to_calendar(const ICU4XDateTime* self, const ICU4XCalendar* calendar);
+
+uint8_t ICU4XDateTime_hour(const ICU4XDateTime* self);
+
+uint8_t ICU4XDateTime_minute(const ICU4XDateTime* self);
+
+uint8_t ICU4XDateTime_second(const ICU4XDateTime* self);
+
+uint32_t ICU4XDateTime_nanosecond(const ICU4XDateTime* self);
+
+uint32_t ICU4XDateTime_day_of_month(const ICU4XDateTime* self);
+
+ICU4XIsoWeekday ICU4XDateTime_day_of_week(const ICU4XDateTime* self);
+
+uint32_t ICU4XDateTime_week_of_month(const ICU4XDateTime* self, ICU4XIsoWeekday first_weekday);
+
+diplomat_result_ICU4XWeekOf_ICU4XError ICU4XDateTime_week_of_year(const ICU4XDateTime* self, const ICU4XWeekCalculator* calculator);
+
+uint32_t ICU4XDateTime_ordinal_month(const ICU4XDateTime* self);
+
+diplomat_result_void_ICU4XError ICU4XDateTime_month_code(const ICU4XDateTime* self, DiplomatWriteable* write);
+
+int32_t ICU4XDateTime_year_in_era(const ICU4XDateTime* self);
+
+diplomat_result_void_ICU4XError ICU4XDateTime_era(const ICU4XDateTime* self, DiplomatWriteable* write);
+
+uint8_t ICU4XDateTime_months_in_year(const ICU4XDateTime* self);
+
+uint8_t ICU4XDateTime_days_in_month(const ICU4XDateTime* self);
+
+uint16_t ICU4XDateTime_days_in_year(const ICU4XDateTime* self);
+
+ICU4XCalendar* ICU4XDateTime_calendar(const ICU4XDateTime* self);
+void ICU4XDateTime_destroy(ICU4XDateTime* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDateTimeFormatter.h b/intl/icu_capi/c/include/ICU4XDateTimeFormatter.h
new file mode 100644
index 0000000000..5f0af4ddba
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDateTimeFormatter.h
@@ -0,0 +1,41 @@
+#ifndef ICU4XDateTimeFormatter_H
+#define ICU4XDateTimeFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDateTimeFormatter ICU4XDateTimeFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "ICU4XTimeLength.h"
+#include "diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError.h"
+#include "ICU4XDateTime.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError ICU4XDateTimeFormatter_create_with_lengths(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length);
+
+diplomat_result_void_ICU4XError ICU4XDateTimeFormatter_format_datetime(const ICU4XDateTimeFormatter* self, const ICU4XDateTime* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XDateTimeFormatter_format_iso_datetime(const ICU4XDateTimeFormatter* self, const ICU4XIsoDateTime* value, DiplomatWriteable* write);
+void ICU4XDateTimeFormatter_destroy(ICU4XDateTimeFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDecomposed.h b/intl/icu_capi/c/include/ICU4XDecomposed.h
new file mode 100644
index 0000000000..3f287e8192
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDecomposed.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XDecomposed_H
+#define ICU4XDecomposed_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDecomposed {
+    char32_t first;
+    char32_t second;
+} ICU4XDecomposed;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XDecomposed_destroy(ICU4XDecomposed* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDecomposingNormalizer.h b/intl/icu_capi/c/include/ICU4XDecomposingNormalizer.h
new file mode 100644
index 0000000000..f542f7a730
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDecomposingNormalizer.h
@@ -0,0 +1,38 @@
+#ifndef ICU4XDecomposingNormalizer_H
+#define ICU4XDecomposingNormalizer_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDecomposingNormalizer ICU4XDecomposingNormalizer;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError ICU4XDecomposingNormalizer_create_nfd(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError ICU4XDecomposingNormalizer_create_nfkd(const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XDecomposingNormalizer_normalize(const ICU4XDecomposingNormalizer* self, const char* s_data, size_t s_len, DiplomatWriteable* write);
+
+bool ICU4XDecomposingNormalizer_is_normalized(const ICU4XDecomposingNormalizer* self, const char* s_data, size_t s_len);
+void ICU4XDecomposingNormalizer_destroy(ICU4XDecomposingNormalizer* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDisplayNamesFallback.h b/intl/icu_capi/c/include/ICU4XDisplayNamesFallback.h
new file mode 100644
index 0000000000..085fc8de5d
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDisplayNamesFallback.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XDisplayNamesFallback_H
+#define ICU4XDisplayNamesFallback_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XDisplayNamesFallback {
+  ICU4XDisplayNamesFallback_Code = 0,
+  ICU4XDisplayNamesFallback_None = 1,
+} ICU4XDisplayNamesFallback;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XDisplayNamesFallback_destroy(ICU4XDisplayNamesFallback* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDisplayNamesOptionsV1.h b/intl/icu_capi/c/include/ICU4XDisplayNamesOptionsV1.h
new file mode 100644
index 0000000000..e998cde0e7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDisplayNamesOptionsV1.h
@@ -0,0 +1,38 @@
+#ifndef ICU4XDisplayNamesOptionsV1_H
+#define ICU4XDisplayNamesOptionsV1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XDisplayNamesStyle.h"
+#include "ICU4XDisplayNamesFallback.h"
+#include "ICU4XLanguageDisplay.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XDisplayNamesOptionsV1 {
+    ICU4XDisplayNamesStyle style;
+    ICU4XDisplayNamesFallback fallback;
+    ICU4XLanguageDisplay language_display;
+} ICU4XDisplayNamesOptionsV1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDisplayNamesStyle.h"
+#include "ICU4XDisplayNamesFallback.h"
+#include "ICU4XLanguageDisplay.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XDisplayNamesOptionsV1_destroy(ICU4XDisplayNamesOptionsV1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XDisplayNamesStyle.h b/intl/icu_capi/c/include/ICU4XDisplayNamesStyle.h
new file mode 100644
index 0000000000..048da455da
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XDisplayNamesStyle.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XDisplayNamesStyle_H
+#define ICU4XDisplayNamesStyle_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XDisplayNamesStyle {
+  ICU4XDisplayNamesStyle_Auto = 0,
+  ICU4XDisplayNamesStyle_Narrow = 1,
+  ICU4XDisplayNamesStyle_Short = 2,
+  ICU4XDisplayNamesStyle_Long = 3,
+  ICU4XDisplayNamesStyle_Menu = 4,
+} ICU4XDisplayNamesStyle;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XDisplayNamesStyle_destroy(ICU4XDisplayNamesStyle* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XError.h b/intl/icu_capi/c/include/ICU4XError.h
new file mode 100644
index 0000000000..8836275ac5
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XError.h
@@ -0,0 +1,84 @@
+#ifndef ICU4XError_H
+#define ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XError {
+  ICU4XError_UnknownError = 0,
+  ICU4XError_WriteableError = 1,
+  ICU4XError_OutOfBoundsError = 2,
+  ICU4XError_DataMissingDataKeyError = 256,
+  ICU4XError_DataMissingVariantError = 257,
+  ICU4XError_DataMissingLocaleError = 258,
+  ICU4XError_DataNeedsVariantError = 259,
+  ICU4XError_DataNeedsLocaleError = 260,
+  ICU4XError_DataExtraneousLocaleError = 261,
+  ICU4XError_DataFilteredResourceError = 262,
+  ICU4XError_DataMismatchedTypeError = 263,
+  ICU4XError_DataMissingPayloadError = 264,
+  ICU4XError_DataInvalidStateError = 265,
+  ICU4XError_DataCustomError = 266,
+  ICU4XError_DataIoError = 267,
+  ICU4XError_DataUnavailableBufferFormatError = 268,
+  ICU4XError_DataMismatchedAnyBufferError = 269,
+  ICU4XError_LocaleUndefinedSubtagError = 512,
+  ICU4XError_LocaleParserLanguageError = 513,
+  ICU4XError_LocaleParserSubtagError = 514,
+  ICU4XError_LocaleParserExtensionError = 515,
+  ICU4XError_DataStructValidityError = 768,
+  ICU4XError_PropertyUnknownScriptIdError = 1024,
+  ICU4XError_PropertyUnknownGeneralCategoryGroupError = 1025,
+  ICU4XError_PropertyUnexpectedPropertyNameError = 1026,
+  ICU4XError_FixedDecimalLimitError = 1280,
+  ICU4XError_FixedDecimalSyntaxError = 1281,
+  ICU4XError_PluralsParserError = 1536,
+  ICU4XError_CalendarParseError = 1792,
+  ICU4XError_CalendarOverflowError = 1793,
+  ICU4XError_CalendarUnderflowError = 1794,
+  ICU4XError_CalendarOutOfRangeError = 1795,
+  ICU4XError_CalendarUnknownEraError = 1796,
+  ICU4XError_CalendarUnknownMonthCodeError = 1797,
+  ICU4XError_CalendarMissingInputError = 1798,
+  ICU4XError_CalendarUnknownKindError = 1799,
+  ICU4XError_CalendarMissingError = 1800,
+  ICU4XError_DateTimePatternError = 2048,
+  ICU4XError_DateTimeMissingInputFieldError = 2049,
+  ICU4XError_DateTimeSkeletonError = 2050,
+  ICU4XError_DateTimeUnsupportedFieldError = 2051,
+  ICU4XError_DateTimeUnsupportedOptionsError = 2052,
+  ICU4XError_DateTimeMissingWeekdaySymbolError = 2053,
+  ICU4XError_DateTimeMissingMonthSymbolError = 2054,
+  ICU4XError_DateTimeFixedDecimalError = 2055,
+  ICU4XError_DateTimeMismatchedCalendarError = 2056,
+  ICU4XError_TinyStrTooLargeError = 2304,
+  ICU4XError_TinyStrContainsNullError = 2305,
+  ICU4XError_TinyStrNonAsciiError = 2306,
+  ICU4XError_TimeZoneOffsetOutOfBoundsError = 2560,
+  ICU4XError_TimeZoneInvalidOffsetError = 2561,
+  ICU4XError_TimeZoneMissingInputError = 2562,
+  ICU4XError_TimeZoneInvalidIdError = 2563,
+  ICU4XError_NormalizerFutureExtensionError = 2816,
+  ICU4XError_NormalizerValidationError = 2817,
+} ICU4XError;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XError_destroy(ICU4XError* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XFixedDecimal.h b/intl/icu_capi/c/include/ICU4XFixedDecimal.h
new file mode 100644
index 0000000000..361294b687
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XFixedDecimal.h
@@ -0,0 +1,101 @@
+#ifndef ICU4XFixedDecimal_H
+#define ICU4XFixedDecimal_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XFixedDecimal ICU4XFixedDecimal;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XFixedDecimal_ICU4XError.h"
+#include "ICU4XFixedDecimalSign.h"
+#include "ICU4XFixedDecimalSignDisplay.h"
+#include "diplomat_result_void_void.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XFixedDecimal* ICU4XFixedDecimal_create_from_i32(int32_t v);
+
+ICU4XFixedDecimal* ICU4XFixedDecimal_create_from_u32(uint32_t v);
+
+ICU4XFixedDecimal* ICU4XFixedDecimal_create_from_i64(int64_t v);
+
+ICU4XFixedDecimal* ICU4XFixedDecimal_create_from_u64(uint64_t v);
+
+diplomat_result_box_ICU4XFixedDecimal_ICU4XError ICU4XFixedDecimal_create_from_f64_with_integer_precision(double f);
+
+diplomat_result_box_ICU4XFixedDecimal_ICU4XError ICU4XFixedDecimal_create_from_f64_with_lower_magnitude(double f, int16_t magnitude);
+
+diplomat_result_box_ICU4XFixedDecimal_ICU4XError ICU4XFixedDecimal_create_from_f64_with_significant_digits(double f, uint8_t digits);
+
+diplomat_result_box_ICU4XFixedDecimal_ICU4XError ICU4XFixedDecimal_create_from_f64_with_floating_precision(double f);
+
+diplomat_result_box_ICU4XFixedDecimal_ICU4XError ICU4XFixedDecimal_create_from_string(const char* v_data, size_t v_len);
+
+uint8_t ICU4XFixedDecimal_digit_at(const ICU4XFixedDecimal* self, int16_t magnitude);
+
+int16_t ICU4XFixedDecimal_magnitude_start(const ICU4XFixedDecimal* self);
+
+int16_t ICU4XFixedDecimal_magnitude_end(const ICU4XFixedDecimal* self);
+
+int16_t ICU4XFixedDecimal_nonzero_magnitude_start(const ICU4XFixedDecimal* self);
+
+int16_t ICU4XFixedDecimal_nonzero_magnitude_end(const ICU4XFixedDecimal* self);
+
+bool ICU4XFixedDecimal_is_zero(const ICU4XFixedDecimal* self);
+
+void ICU4XFixedDecimal_multiply_pow10(ICU4XFixedDecimal* self, int16_t power);
+
+ICU4XFixedDecimalSign ICU4XFixedDecimal_sign(const ICU4XFixedDecimal* self);
+
+void ICU4XFixedDecimal_set_sign(ICU4XFixedDecimal* self, ICU4XFixedDecimalSign sign);
+
+void ICU4XFixedDecimal_apply_sign_display(ICU4XFixedDecimal* self, ICU4XFixedDecimalSignDisplay sign_display);
+
+void ICU4XFixedDecimal_trim_start(ICU4XFixedDecimal* self);
+
+void ICU4XFixedDecimal_trim_end(ICU4XFixedDecimal* self);
+
+void ICU4XFixedDecimal_pad_start(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_pad_end(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_set_max_position(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_trunc(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_half_trunc(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_expand(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_half_expand(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_ceil(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_half_ceil(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_floor(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_half_floor(ICU4XFixedDecimal* self, int16_t position);
+
+void ICU4XFixedDecimal_half_even(ICU4XFixedDecimal* self, int16_t position);
+
+diplomat_result_void_void ICU4XFixedDecimal_concatenate_end(ICU4XFixedDecimal* self, ICU4XFixedDecimal* other);
+
+void ICU4XFixedDecimal_to_string(const ICU4XFixedDecimal* self, DiplomatWriteable* to);
+void ICU4XFixedDecimal_destroy(ICU4XFixedDecimal* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XFixedDecimalFormatter.h b/intl/icu_capi/c/include/ICU4XFixedDecimalFormatter.h
new file mode 100644
index 0000000000..aa1cfd6a48
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XFixedDecimalFormatter.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XFixedDecimalFormatter_H
+#define ICU4XFixedDecimalFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XFixedDecimalFormatter ICU4XFixedDecimalFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XFixedDecimalGroupingStrategy.h"
+#include "diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError.h"
+#include "ICU4XDataStruct.h"
+#include "ICU4XFixedDecimal.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError ICU4XFixedDecimalFormatter_create_with_grouping_strategy(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XFixedDecimalGroupingStrategy grouping_strategy);
+
+diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError ICU4XFixedDecimalFormatter_create_with_decimal_symbols_v1(const ICU4XDataStruct* data_struct, ICU4XFixedDecimalGroupingStrategy grouping_strategy);
+
+diplomat_result_void_ICU4XError ICU4XFixedDecimalFormatter_format(const ICU4XFixedDecimalFormatter* self, const ICU4XFixedDecimal* value, DiplomatWriteable* write);
+void ICU4XFixedDecimalFormatter_destroy(ICU4XFixedDecimalFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XFixedDecimalGroupingStrategy.h b/intl/icu_capi/c/include/ICU4XFixedDecimalGroupingStrategy.h
new file mode 100644
index 0000000000..7648892cc5
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XFixedDecimalGroupingStrategy.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XFixedDecimalGroupingStrategy_H
+#define ICU4XFixedDecimalGroupingStrategy_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XFixedDecimalGroupingStrategy {
+  ICU4XFixedDecimalGroupingStrategy_Auto = 0,
+  ICU4XFixedDecimalGroupingStrategy_Never = 1,
+  ICU4XFixedDecimalGroupingStrategy_Always = 2,
+  ICU4XFixedDecimalGroupingStrategy_Min2 = 3,
+} ICU4XFixedDecimalGroupingStrategy;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XFixedDecimalGroupingStrategy_destroy(ICU4XFixedDecimalGroupingStrategy* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XFixedDecimalSign.h b/intl/icu_capi/c/include/ICU4XFixedDecimalSign.h
new file mode 100644
index 0000000000..12fff3cf1c
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XFixedDecimalSign.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XFixedDecimalSign_H
+#define ICU4XFixedDecimalSign_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XFixedDecimalSign {
+  ICU4XFixedDecimalSign_None = 0,
+  ICU4XFixedDecimalSign_Negative = 1,
+  ICU4XFixedDecimalSign_Positive = 2,
+} ICU4XFixedDecimalSign;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XFixedDecimalSign_destroy(ICU4XFixedDecimalSign* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XFixedDecimalSignDisplay.h b/intl/icu_capi/c/include/ICU4XFixedDecimalSignDisplay.h
new file mode 100644
index 0000000000..8c2612e516
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XFixedDecimalSignDisplay.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XFixedDecimalSignDisplay_H
+#define ICU4XFixedDecimalSignDisplay_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XFixedDecimalSignDisplay {
+  ICU4XFixedDecimalSignDisplay_Auto = 0,
+  ICU4XFixedDecimalSignDisplay_Never = 1,
+  ICU4XFixedDecimalSignDisplay_Always = 2,
+  ICU4XFixedDecimalSignDisplay_ExceptZero = 3,
+  ICU4XFixedDecimalSignDisplay_Negative = 4,
+} ICU4XFixedDecimalSignDisplay;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XFixedDecimalSignDisplay_destroy(ICU4XFixedDecimalSignDisplay* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGeneralCategoryNameToMaskMapper.h b/intl/icu_capi/c/include/ICU4XGeneralCategoryNameToMaskMapper.h
new file mode 100644
index 0000000000..3a4e2d4d13
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGeneralCategoryNameToMaskMapper.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XGeneralCategoryNameToMaskMapper_H
+#define ICU4XGeneralCategoryNameToMaskMapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGeneralCategoryNameToMaskMapper ICU4XGeneralCategoryNameToMaskMapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+uint32_t ICU4XGeneralCategoryNameToMaskMapper_get_strict(const ICU4XGeneralCategoryNameToMaskMapper* self, const char* name_data, size_t name_len);
+
+uint32_t ICU4XGeneralCategoryNameToMaskMapper_get_loose(const ICU4XGeneralCategoryNameToMaskMapper* self, const char* name_data, size_t name_len);
+
+diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError ICU4XGeneralCategoryNameToMaskMapper_load(const ICU4XDataProvider* provider);
+void ICU4XGeneralCategoryNameToMaskMapper_destroy(ICU4XGeneralCategoryNameToMaskMapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorLatin1.h b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorLatin1.h
new file mode 100644
index 0000000000..9e23489fd3
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorLatin1.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XGraphemeClusterBreakIteratorLatin1_H
+#define ICU4XGraphemeClusterBreakIteratorLatin1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGraphemeClusterBreakIteratorLatin1 ICU4XGraphemeClusterBreakIteratorLatin1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XGraphemeClusterBreakIteratorLatin1_next(ICU4XGraphemeClusterBreakIteratorLatin1* self);
+void ICU4XGraphemeClusterBreakIteratorLatin1_destroy(ICU4XGraphemeClusterBreakIteratorLatin1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf16.h b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf16.h
new file mode 100644
index 0000000000..f0de4c0214
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf16.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XGraphemeClusterBreakIteratorUtf16_H
+#define ICU4XGraphemeClusterBreakIteratorUtf16_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGraphemeClusterBreakIteratorUtf16 ICU4XGraphemeClusterBreakIteratorUtf16;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XGraphemeClusterBreakIteratorUtf16_next(ICU4XGraphemeClusterBreakIteratorUtf16* self);
+void ICU4XGraphemeClusterBreakIteratorUtf16_destroy(ICU4XGraphemeClusterBreakIteratorUtf16* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf8.h b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf8.h
new file mode 100644
index 0000000000..331b17eac7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGraphemeClusterBreakIteratorUtf8.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XGraphemeClusterBreakIteratorUtf8_H
+#define ICU4XGraphemeClusterBreakIteratorUtf8_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGraphemeClusterBreakIteratorUtf8 ICU4XGraphemeClusterBreakIteratorUtf8;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XGraphemeClusterBreakIteratorUtf8_next(ICU4XGraphemeClusterBreakIteratorUtf8* self);
+void ICU4XGraphemeClusterBreakIteratorUtf8_destroy(ICU4XGraphemeClusterBreakIteratorUtf8* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGraphemeClusterSegmenter.h b/intl/icu_capi/c/include/ICU4XGraphemeClusterSegmenter.h
new file mode 100644
index 0000000000..1805090bfb
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGraphemeClusterSegmenter.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XGraphemeClusterSegmenter_H
+#define ICU4XGraphemeClusterSegmenter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGraphemeClusterSegmenter ICU4XGraphemeClusterSegmenter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError.h"
+#include "ICU4XGraphemeClusterBreakIteratorUtf8.h"
+#include "ICU4XGraphemeClusterBreakIteratorUtf16.h"
+#include "ICU4XGraphemeClusterBreakIteratorLatin1.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError ICU4XGraphemeClusterSegmenter_create(const ICU4XDataProvider* provider);
+
+ICU4XGraphemeClusterBreakIteratorUtf8* ICU4XGraphemeClusterSegmenter_segment_utf8(const ICU4XGraphemeClusterSegmenter* self, const char* input_data, size_t input_len);
+
+ICU4XGraphemeClusterBreakIteratorUtf16* ICU4XGraphemeClusterSegmenter_segment_utf16(const ICU4XGraphemeClusterSegmenter* self, const uint16_t* input_data, size_t input_len);
+
+ICU4XGraphemeClusterBreakIteratorLatin1* ICU4XGraphemeClusterSegmenter_segment_latin1(const ICU4XGraphemeClusterSegmenter* self, const uint8_t* input_data, size_t input_len);
+void ICU4XGraphemeClusterSegmenter_destroy(ICU4XGraphemeClusterSegmenter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGregorianDateFormatter.h b/intl/icu_capi/c/include/ICU4XGregorianDateFormatter.h
new file mode 100644
index 0000000000..cf3ad9e9f4
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGregorianDateFormatter.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XGregorianDateFormatter_H
+#define ICU4XGregorianDateFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGregorianDateFormatter ICU4XGregorianDateFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError.h"
+#include "ICU4XIsoDate.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError ICU4XGregorianDateFormatter_create_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength length);
+
+diplomat_result_void_ICU4XError ICU4XGregorianDateFormatter_format_iso_date(const ICU4XGregorianDateFormatter* self, const ICU4XIsoDate* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XGregorianDateFormatter_format_iso_datetime(const ICU4XGregorianDateFormatter* self, const ICU4XIsoDateTime* value, DiplomatWriteable* write);
+void ICU4XGregorianDateFormatter_destroy(ICU4XGregorianDateFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGregorianDateTimeFormatter.h b/intl/icu_capi/c/include/ICU4XGregorianDateTimeFormatter.h
new file mode 100644
index 0000000000..0b56ddc393
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGregorianDateTimeFormatter.h
@@ -0,0 +1,38 @@
+#ifndef ICU4XGregorianDateTimeFormatter_H
+#define ICU4XGregorianDateTimeFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGregorianDateTimeFormatter ICU4XGregorianDateTimeFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "ICU4XTimeLength.h"
+#include "diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError.h"
+#include "ICU4XIsoDateTime.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError ICU4XGregorianDateTimeFormatter_create_with_lengths(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length);
+
+diplomat_result_void_ICU4XError ICU4XGregorianDateTimeFormatter_format_iso_datetime(const ICU4XGregorianDateTimeFormatter* self, const ICU4XIsoDateTime* value, DiplomatWriteable* write);
+void ICU4XGregorianDateTimeFormatter_destroy(ICU4XGregorianDateTimeFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XGregorianZonedDateTimeFormatter.h b/intl/icu_capi/c/include/ICU4XGregorianZonedDateTimeFormatter.h
new file mode 100644
index 0000000000..4be60c2b0b
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XGregorianZonedDateTimeFormatter.h
@@ -0,0 +1,42 @@
+#ifndef ICU4XGregorianZonedDateTimeFormatter_H
+#define ICU4XGregorianZonedDateTimeFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XGregorianZonedDateTimeFormatter ICU4XGregorianZonedDateTimeFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "ICU4XTimeLength.h"
+#include "diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError.h"
+#include "ICU4XIsoTimeZoneOptions.h"
+#include "ICU4XIsoDateTime.h"
+#include "ICU4XCustomTimeZone.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError ICU4XGregorianZonedDateTimeFormatter_create_with_lengths(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length);
+
+diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError ICU4XGregorianZonedDateTimeFormatter_create_with_lengths_and_iso_8601_time_zone_fallback(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length, ICU4XIsoTimeZoneOptions zone_options);
+
+diplomat_result_void_ICU4XError ICU4XGregorianZonedDateTimeFormatter_format_iso_datetime_with_custom_time_zone(const ICU4XGregorianZonedDateTimeFormatter* self, const ICU4XIsoDateTime* datetime, const ICU4XCustomTimeZone* time_zone, DiplomatWriteable* write);
+void ICU4XGregorianZonedDateTimeFormatter_destroy(ICU4XGregorianZonedDateTimeFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIanaToBcp47Mapper.h b/intl/icu_capi/c/include/ICU4XIanaToBcp47Mapper.h
new file mode 100644
index 0000000000..e06433b6d0
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIanaToBcp47Mapper.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XIanaToBcp47Mapper_H
+#define ICU4XIanaToBcp47Mapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XIanaToBcp47Mapper ICU4XIanaToBcp47Mapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError ICU4XIanaToBcp47Mapper_create(const ICU4XDataProvider* provider);
+void ICU4XIanaToBcp47Mapper_destroy(ICU4XIanaToBcp47Mapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoDate.h b/intl/icu_capi/c/include/ICU4XIsoDate.h
new file mode 100644
index 0000000000..d7a018244a
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoDate.h
@@ -0,0 +1,61 @@
+#ifndef ICU4XIsoDate_H
+#define ICU4XIsoDate_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XIsoDate ICU4XIsoDate;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XIsoDate_ICU4XError.h"
+#include "ICU4XCalendar.h"
+#include "ICU4XDate.h"
+#include "ICU4XIsoWeekday.h"
+#include "ICU4XWeekCalculator.h"
+#include "diplomat_result_ICU4XWeekOf_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XIsoDate_ICU4XError ICU4XIsoDate_create(int32_t year, uint8_t month, uint8_t day);
+
+ICU4XIsoDate* ICU4XIsoDate_create_for_unix_epoch();
+
+ICU4XDate* ICU4XIsoDate_to_calendar(const ICU4XIsoDate* self, const ICU4XCalendar* calendar);
+
+ICU4XDate* ICU4XIsoDate_to_any(const ICU4XIsoDate* self);
+
+uint32_t ICU4XIsoDate_day_of_month(const ICU4XIsoDate* self);
+
+ICU4XIsoWeekday ICU4XIsoDate_day_of_week(const ICU4XIsoDate* self);
+
+uint32_t ICU4XIsoDate_week_of_month(const ICU4XIsoDate* self, ICU4XIsoWeekday first_weekday);
+
+diplomat_result_ICU4XWeekOf_ICU4XError ICU4XIsoDate_week_of_year(const ICU4XIsoDate* self, const ICU4XWeekCalculator* calculator);
+
+uint32_t ICU4XIsoDate_month(const ICU4XIsoDate* self);
+
+int32_t ICU4XIsoDate_year(const ICU4XIsoDate* self);
+
+bool ICU4XIsoDate_is_in_leap_year(const ICU4XIsoDate* self);
+
+uint8_t ICU4XIsoDate_months_in_year(const ICU4XIsoDate* self);
+
+uint8_t ICU4XIsoDate_days_in_month(const ICU4XIsoDate* self);
+
+uint16_t ICU4XIsoDate_days_in_year(const ICU4XIsoDate* self);
+void ICU4XIsoDate_destroy(ICU4XIsoDate* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoDateTime.h b/intl/icu_capi/c/include/ICU4XIsoDateTime.h
new file mode 100644
index 0000000000..404cbfedc8
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoDateTime.h
@@ -0,0 +1,79 @@
+#ifndef ICU4XIsoDateTime_H
+#define ICU4XIsoDateTime_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XIsoDateTime ICU4XIsoDateTime;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XIsoDateTime_ICU4XError.h"
+#include "ICU4XIsoDate.h"
+#include "ICU4XTime.h"
+#include "ICU4XDateTime.h"
+#include "ICU4XCalendar.h"
+#include "ICU4XIsoWeekday.h"
+#include "ICU4XWeekCalculator.h"
+#include "diplomat_result_ICU4XWeekOf_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XIsoDateTime_ICU4XError ICU4XIsoDateTime_create(int32_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second, uint32_t nanosecond);
+
+ICU4XIsoDateTime* ICU4XIsoDateTime_crate_from_date_and_time(const ICU4XIsoDate* date, const ICU4XTime* time);
+
+ICU4XIsoDateTime* ICU4XIsoDateTime_create_from_minutes_since_local_unix_epoch(int32_t minutes);
+
+ICU4XIsoDate* ICU4XIsoDateTime_date(const ICU4XIsoDateTime* self);
+
+ICU4XTime* ICU4XIsoDateTime_time(const ICU4XIsoDateTime* self);
+
+ICU4XDateTime* ICU4XIsoDateTime_to_any(const ICU4XIsoDateTime* self);
+
+int32_t ICU4XIsoDateTime_minutes_since_local_unix_epoch(const ICU4XIsoDateTime* self);
+
+ICU4XDateTime* ICU4XIsoDateTime_to_calendar(const ICU4XIsoDateTime* self, const ICU4XCalendar* calendar);
+
+uint8_t ICU4XIsoDateTime_hour(const ICU4XIsoDateTime* self);
+
+uint8_t ICU4XIsoDateTime_minute(const ICU4XIsoDateTime* self);
+
+uint8_t ICU4XIsoDateTime_second(const ICU4XIsoDateTime* self);
+
+uint32_t ICU4XIsoDateTime_nanosecond(const ICU4XIsoDateTime* self);
+
+uint32_t ICU4XIsoDateTime_day_of_month(const ICU4XIsoDateTime* self);
+
+ICU4XIsoWeekday ICU4XIsoDateTime_day_of_week(const ICU4XIsoDateTime* self);
+
+uint32_t ICU4XIsoDateTime_week_of_month(const ICU4XIsoDateTime* self, ICU4XIsoWeekday first_weekday);
+
+diplomat_result_ICU4XWeekOf_ICU4XError ICU4XIsoDateTime_week_of_year(const ICU4XIsoDateTime* self, const ICU4XWeekCalculator* calculator);
+
+uint32_t ICU4XIsoDateTime_month(const ICU4XIsoDateTime* self);
+
+int32_t ICU4XIsoDateTime_year(const ICU4XIsoDateTime* self);
+
+bool ICU4XIsoDateTime_is_in_leap_year(const ICU4XIsoDateTime* self);
+
+uint8_t ICU4XIsoDateTime_months_in_year(const ICU4XIsoDateTime* self);
+
+uint8_t ICU4XIsoDateTime_days_in_month(const ICU4XIsoDateTime* self);
+
+uint16_t ICU4XIsoDateTime_days_in_year(const ICU4XIsoDateTime* self);
+void ICU4XIsoDateTime_destroy(ICU4XIsoDateTime* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoTimeZoneFormat.h b/intl/icu_capi/c/include/ICU4XIsoTimeZoneFormat.h
new file mode 100644
index 0000000000..e48a1142f2
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoTimeZoneFormat.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XIsoTimeZoneFormat_H
+#define ICU4XIsoTimeZoneFormat_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XIsoTimeZoneFormat {
+  ICU4XIsoTimeZoneFormat_Basic = 0,
+  ICU4XIsoTimeZoneFormat_Extended = 1,
+  ICU4XIsoTimeZoneFormat_UtcBasic = 2,
+  ICU4XIsoTimeZoneFormat_UtcExtended = 3,
+} ICU4XIsoTimeZoneFormat;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XIsoTimeZoneFormat_destroy(ICU4XIsoTimeZoneFormat* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoTimeZoneMinuteDisplay.h b/intl/icu_capi/c/include/ICU4XIsoTimeZoneMinuteDisplay.h
new file mode 100644
index 0000000000..edeee97019
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoTimeZoneMinuteDisplay.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XIsoTimeZoneMinuteDisplay_H
+#define ICU4XIsoTimeZoneMinuteDisplay_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XIsoTimeZoneMinuteDisplay {
+  ICU4XIsoTimeZoneMinuteDisplay_Required = 0,
+  ICU4XIsoTimeZoneMinuteDisplay_Optional = 1,
+} ICU4XIsoTimeZoneMinuteDisplay;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XIsoTimeZoneMinuteDisplay_destroy(ICU4XIsoTimeZoneMinuteDisplay* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoTimeZoneOptions.h b/intl/icu_capi/c/include/ICU4XIsoTimeZoneOptions.h
new file mode 100644
index 0000000000..7ba051c3e6
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoTimeZoneOptions.h
@@ -0,0 +1,38 @@
+#ifndef ICU4XIsoTimeZoneOptions_H
+#define ICU4XIsoTimeZoneOptions_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XIsoTimeZoneFormat.h"
+#include "ICU4XIsoTimeZoneMinuteDisplay.h"
+#include "ICU4XIsoTimeZoneSecondDisplay.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XIsoTimeZoneOptions {
+    ICU4XIsoTimeZoneFormat format;
+    ICU4XIsoTimeZoneMinuteDisplay minutes;
+    ICU4XIsoTimeZoneSecondDisplay seconds;
+} ICU4XIsoTimeZoneOptions;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XIsoTimeZoneFormat.h"
+#include "ICU4XIsoTimeZoneMinuteDisplay.h"
+#include "ICU4XIsoTimeZoneSecondDisplay.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XIsoTimeZoneOptions_destroy(ICU4XIsoTimeZoneOptions* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoTimeZoneSecondDisplay.h b/intl/icu_capi/c/include/ICU4XIsoTimeZoneSecondDisplay.h
new file mode 100644
index 0000000000..487a248f95
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoTimeZoneSecondDisplay.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XIsoTimeZoneSecondDisplay_H
+#define ICU4XIsoTimeZoneSecondDisplay_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XIsoTimeZoneSecondDisplay {
+  ICU4XIsoTimeZoneSecondDisplay_Optional = 0,
+  ICU4XIsoTimeZoneSecondDisplay_Never = 1,
+} ICU4XIsoTimeZoneSecondDisplay;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XIsoTimeZoneSecondDisplay_destroy(ICU4XIsoTimeZoneSecondDisplay* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XIsoWeekday.h b/intl/icu_capi/c/include/ICU4XIsoWeekday.h
new file mode 100644
index 0000000000..a23d0a3b9e
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XIsoWeekday.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XIsoWeekday_H
+#define ICU4XIsoWeekday_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XIsoWeekday {
+  ICU4XIsoWeekday_Monday = 1,
+  ICU4XIsoWeekday_Tuesday = 2,
+  ICU4XIsoWeekday_Wednesday = 3,
+  ICU4XIsoWeekday_Thursday = 4,
+  ICU4XIsoWeekday_Friday = 5,
+  ICU4XIsoWeekday_Saturday = 6,
+  ICU4XIsoWeekday_Sunday = 7,
+} ICU4XIsoWeekday;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XIsoWeekday_destroy(ICU4XIsoWeekday* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLanguageDisplay.h b/intl/icu_capi/c/include/ICU4XLanguageDisplay.h
new file mode 100644
index 0000000000..0b921351fe
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLanguageDisplay.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XLanguageDisplay_H
+#define ICU4XLanguageDisplay_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLanguageDisplay {
+  ICU4XLanguageDisplay_Dialect = 0,
+  ICU4XLanguageDisplay_Standard = 1,
+} ICU4XLanguageDisplay;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLanguageDisplay_destroy(ICU4XLanguageDisplay* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLeadingAdjustment.h b/intl/icu_capi/c/include/ICU4XLeadingAdjustment.h
new file mode 100644
index 0000000000..91647188ed
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLeadingAdjustment.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XLeadingAdjustment_H
+#define ICU4XLeadingAdjustment_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLeadingAdjustment {
+  ICU4XLeadingAdjustment_Auto = 0,
+  ICU4XLeadingAdjustment_None = 1,
+  ICU4XLeadingAdjustment_ToCased = 2,
+} ICU4XLeadingAdjustment;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLeadingAdjustment_destroy(ICU4XLeadingAdjustment* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakIteratorLatin1.h b/intl/icu_capi/c/include/ICU4XLineBreakIteratorLatin1.h
new file mode 100644
index 0000000000..c1a4c39131
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakIteratorLatin1.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XLineBreakIteratorLatin1_H
+#define ICU4XLineBreakIteratorLatin1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLineBreakIteratorLatin1 ICU4XLineBreakIteratorLatin1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XLineBreakIteratorLatin1_next(ICU4XLineBreakIteratorLatin1* self);
+void ICU4XLineBreakIteratorLatin1_destroy(ICU4XLineBreakIteratorLatin1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf16.h b/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf16.h
new file mode 100644
index 0000000000..78ae12c7e4
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf16.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XLineBreakIteratorUtf16_H
+#define ICU4XLineBreakIteratorUtf16_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLineBreakIteratorUtf16 ICU4XLineBreakIteratorUtf16;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XLineBreakIteratorUtf16_next(ICU4XLineBreakIteratorUtf16* self);
+void ICU4XLineBreakIteratorUtf16_destroy(ICU4XLineBreakIteratorUtf16* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf8.h b/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf8.h
new file mode 100644
index 0000000000..3a08c5ad23
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakIteratorUtf8.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XLineBreakIteratorUtf8_H
+#define ICU4XLineBreakIteratorUtf8_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLineBreakIteratorUtf8 ICU4XLineBreakIteratorUtf8;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XLineBreakIteratorUtf8_next(ICU4XLineBreakIteratorUtf8* self);
+void ICU4XLineBreakIteratorUtf8_destroy(ICU4XLineBreakIteratorUtf8* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakOptionsV1.h b/intl/icu_capi/c/include/ICU4XLineBreakOptionsV1.h
new file mode 100644
index 0000000000..5fbf4b5814
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakOptionsV1.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XLineBreakOptionsV1_H
+#define ICU4XLineBreakOptionsV1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XLineBreakStrictness.h"
+#include "ICU4XLineBreakWordOption.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLineBreakOptionsV1 {
+    ICU4XLineBreakStrictness strictness;
+    ICU4XLineBreakWordOption word_option;
+    bool ja_zh;
+} ICU4XLineBreakOptionsV1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLineBreakStrictness.h"
+#include "ICU4XLineBreakWordOption.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLineBreakOptionsV1_destroy(ICU4XLineBreakOptionsV1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakStrictness.h b/intl/icu_capi/c/include/ICU4XLineBreakStrictness.h
new file mode 100644
index 0000000000..e3534b7ec7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakStrictness.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XLineBreakStrictness_H
+#define ICU4XLineBreakStrictness_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLineBreakStrictness {
+  ICU4XLineBreakStrictness_Loose = 0,
+  ICU4XLineBreakStrictness_Normal = 1,
+  ICU4XLineBreakStrictness_Strict = 2,
+  ICU4XLineBreakStrictness_Anywhere = 3,
+} ICU4XLineBreakStrictness;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLineBreakStrictness_destroy(ICU4XLineBreakStrictness* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineBreakWordOption.h b/intl/icu_capi/c/include/ICU4XLineBreakWordOption.h
new file mode 100644
index 0000000000..02a6ca6f2d
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineBreakWordOption.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XLineBreakWordOption_H
+#define ICU4XLineBreakWordOption_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLineBreakWordOption {
+  ICU4XLineBreakWordOption_Normal = 0,
+  ICU4XLineBreakWordOption_BreakAll = 1,
+  ICU4XLineBreakWordOption_KeepAll = 2,
+} ICU4XLineBreakWordOption;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLineBreakWordOption_destroy(ICU4XLineBreakWordOption* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLineSegmenter.h b/intl/icu_capi/c/include/ICU4XLineSegmenter.h
new file mode 100644
index 0000000000..f734ec78f8
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLineSegmenter.h
@@ -0,0 +1,51 @@
+#ifndef ICU4XLineSegmenter_H
+#define ICU4XLineSegmenter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLineSegmenter ICU4XLineSegmenter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XLineSegmenter_ICU4XError.h"
+#include "ICU4XLineBreakOptionsV1.h"
+#include "ICU4XLineBreakIteratorUtf8.h"
+#include "ICU4XLineBreakIteratorUtf16.h"
+#include "ICU4XLineBreakIteratorLatin1.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_auto(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_lstm(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_dictionary(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_auto_with_options_v1(const ICU4XDataProvider* provider, ICU4XLineBreakOptionsV1 options);
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_lstm_with_options_v1(const ICU4XDataProvider* provider, ICU4XLineBreakOptionsV1 options);
+
+diplomat_result_box_ICU4XLineSegmenter_ICU4XError ICU4XLineSegmenter_create_dictionary_with_options_v1(const ICU4XDataProvider* provider, ICU4XLineBreakOptionsV1 options);
+
+ICU4XLineBreakIteratorUtf8* ICU4XLineSegmenter_segment_utf8(const ICU4XLineSegmenter* self, const char* input_data, size_t input_len);
+
+ICU4XLineBreakIteratorUtf16* ICU4XLineSegmenter_segment_utf16(const ICU4XLineSegmenter* self, const uint16_t* input_data, size_t input_len);
+
+ICU4XLineBreakIteratorLatin1* ICU4XLineSegmenter_segment_latin1(const ICU4XLineSegmenter* self, const uint8_t* input_data, size_t input_len);
+void ICU4XLineSegmenter_destroy(ICU4XLineSegmenter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XList.h b/intl/icu_capi/c/include/ICU4XList.h
new file mode 100644
index 0000000000..6549561c37
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XList.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XList_H
+#define ICU4XList_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XList ICU4XList;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XList* ICU4XList_create();
+
+ICU4XList* ICU4XList_create_with_capacity(size_t capacity);
+
+void ICU4XList_push(ICU4XList* self, const char* val_data, size_t val_len);
+
+size_t ICU4XList_len(const ICU4XList* self);
+void ICU4XList_destroy(ICU4XList* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XListFormatter.h b/intl/icu_capi/c/include/ICU4XListFormatter.h
new file mode 100644
index 0000000000..ee358dc254
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XListFormatter.h
@@ -0,0 +1,41 @@
+#ifndef ICU4XListFormatter_H
+#define ICU4XListFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XListFormatter ICU4XListFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XListLength.h"
+#include "diplomat_result_box_ICU4XListFormatter_ICU4XError.h"
+#include "ICU4XList.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XListFormatter_ICU4XError ICU4XListFormatter_create_and_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XListLength length);
+
+diplomat_result_box_ICU4XListFormatter_ICU4XError ICU4XListFormatter_create_or_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XListLength length);
+
+diplomat_result_box_ICU4XListFormatter_ICU4XError ICU4XListFormatter_create_unit_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XListLength length);
+
+diplomat_result_void_ICU4XError ICU4XListFormatter_format(const ICU4XListFormatter* self, const ICU4XList* list, DiplomatWriteable* write);
+void ICU4XListFormatter_destroy(ICU4XListFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XListLength.h b/intl/icu_capi/c/include/ICU4XListLength.h
new file mode 100644
index 0000000000..7092f6d9df
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XListLength.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XListLength_H
+#define ICU4XListLength_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XListLength {
+  ICU4XListLength_Wide = 0,
+  ICU4XListLength_Short = 1,
+  ICU4XListLength_Narrow = 2,
+} ICU4XListLength;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XListLength_destroy(ICU4XListLength* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocale.h b/intl/icu_capi/c/include/ICU4XLocale.h
new file mode 100644
index 0000000000..dea8d196b5
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocale.h
@@ -0,0 +1,64 @@
+#ifndef ICU4XLocale_H
+#define ICU4XLocale_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocale ICU4XLocale;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XLocale_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XOrdering.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocale_ICU4XError ICU4XLocale_create_from_string(const char* name_data, size_t name_len);
+
+ICU4XLocale* ICU4XLocale_create_und();
+
+ICU4XLocale* ICU4XLocale_clone(const ICU4XLocale* self);
+
+diplomat_result_void_ICU4XError ICU4XLocale_basename(const ICU4XLocale* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_get_unicode_extension(const ICU4XLocale* self, const char* bytes_data, size_t bytes_len, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_language(const ICU4XLocale* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_set_language(ICU4XLocale* self, const char* bytes_data, size_t bytes_len);
+
+diplomat_result_void_ICU4XError ICU4XLocale_region(const ICU4XLocale* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_set_region(ICU4XLocale* self, const char* bytes_data, size_t bytes_len);
+
+diplomat_result_void_ICU4XError ICU4XLocale_script(const ICU4XLocale* self, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_set_script(ICU4XLocale* self, const char* bytes_data, size_t bytes_len);
+
+diplomat_result_void_ICU4XError ICU4XLocale_canonicalize(const char* bytes_data, size_t bytes_len, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XLocale_to_string(const ICU4XLocale* self, DiplomatWriteable* write);
+
+bool ICU4XLocale_normalizing_eq(const ICU4XLocale* self, const char* other_data, size_t other_len);
+
+ICU4XOrdering ICU4XLocale_strict_cmp(const ICU4XLocale* self, const char* other_data, size_t other_len);
+
+ICU4XLocale* ICU4XLocale_create_en();
+
+ICU4XLocale* ICU4XLocale_create_bn();
+void ICU4XLocale_destroy(ICU4XLocale* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleCanonicalizer.h b/intl/icu_capi/c/include/ICU4XLocaleCanonicalizer.h
new file mode 100644
index 0000000000..8b48ad8bb6
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleCanonicalizer.h
@@ -0,0 +1,37 @@
+#ifndef ICU4XLocaleCanonicalizer_H
+#define ICU4XLocaleCanonicalizer_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleCanonicalizer ICU4XLocaleCanonicalizer;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError.h"
+#include "ICU4XLocale.h"
+#include "ICU4XTransformResult.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError ICU4XLocaleCanonicalizer_create(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError ICU4XLocaleCanonicalizer_create_extended(const ICU4XDataProvider* provider);
+
+ICU4XTransformResult ICU4XLocaleCanonicalizer_canonicalize(const ICU4XLocaleCanonicalizer* self, ICU4XLocale* locale);
+void ICU4XLocaleCanonicalizer_destroy(ICU4XLocaleCanonicalizer* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleDirection.h b/intl/icu_capi/c/include/ICU4XLocaleDirection.h
new file mode 100644
index 0000000000..688f04c98c
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleDirection.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XLocaleDirection_H
+#define ICU4XLocaleDirection_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLocaleDirection {
+  ICU4XLocaleDirection_LeftToRight = 0,
+  ICU4XLocaleDirection_RightToLeft = 1,
+  ICU4XLocaleDirection_Unknown = 2,
+} ICU4XLocaleDirection;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLocaleDirection_destroy(ICU4XLocaleDirection* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleDirectionality.h b/intl/icu_capi/c/include/ICU4XLocaleDirectionality.h
new file mode 100644
index 0000000000..9271b078c7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleDirectionality.h
@@ -0,0 +1,42 @@
+#ifndef ICU4XLocaleDirectionality_H
+#define ICU4XLocaleDirectionality_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleDirectionality ICU4XLocaleDirectionality;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError.h"
+#include "ICU4XLocaleExpander.h"
+#include "ICU4XLocale.h"
+#include "ICU4XLocaleDirection.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError ICU4XLocaleDirectionality_create(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError ICU4XLocaleDirectionality_create_with_expander(const ICU4XDataProvider* provider, const ICU4XLocaleExpander* expander);
+
+ICU4XLocaleDirection ICU4XLocaleDirectionality_get(const ICU4XLocaleDirectionality* self, const ICU4XLocale* locale);
+
+bool ICU4XLocaleDirectionality_is_left_to_right(const ICU4XLocaleDirectionality* self, const ICU4XLocale* locale);
+
+bool ICU4XLocaleDirectionality_is_right_to_left(const ICU4XLocaleDirectionality* self, const ICU4XLocale* locale);
+void ICU4XLocaleDirectionality_destroy(ICU4XLocaleDirectionality* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleDisplayNamesFormatter.h b/intl/icu_capi/c/include/ICU4XLocaleDisplayNamesFormatter.h
new file mode 100644
index 0000000000..bfed8ec411
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleDisplayNamesFormatter.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XLocaleDisplayNamesFormatter_H
+#define ICU4XLocaleDisplayNamesFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleDisplayNamesFormatter ICU4XLocaleDisplayNamesFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDisplayNamesOptionsV1.h"
+#include "diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError ICU4XLocaleDisplayNamesFormatter_create(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDisplayNamesOptionsV1 options);
+
+diplomat_result_void_ICU4XError ICU4XLocaleDisplayNamesFormatter_of(const ICU4XLocaleDisplayNamesFormatter* self, const ICU4XLocale* locale, DiplomatWriteable* write);
+void ICU4XLocaleDisplayNamesFormatter_destroy(ICU4XLocaleDisplayNamesFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleExpander.h b/intl/icu_capi/c/include/ICU4XLocaleExpander.h
new file mode 100644
index 0000000000..a7de7be16b
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleExpander.h
@@ -0,0 +1,39 @@
+#ifndef ICU4XLocaleExpander_H
+#define ICU4XLocaleExpander_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleExpander ICU4XLocaleExpander;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XLocaleExpander_ICU4XError.h"
+#include "ICU4XLocale.h"
+#include "ICU4XTransformResult.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocaleExpander_ICU4XError ICU4XLocaleExpander_create(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XLocaleExpander_ICU4XError ICU4XLocaleExpander_create_extended(const ICU4XDataProvider* provider);
+
+ICU4XTransformResult ICU4XLocaleExpander_maximize(const ICU4XLocaleExpander* self, ICU4XLocale* locale);
+
+ICU4XTransformResult ICU4XLocaleExpander_minimize(const ICU4XLocaleExpander* self, ICU4XLocale* locale);
+void ICU4XLocaleExpander_destroy(ICU4XLocaleExpander* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbackConfig.h b/intl/icu_capi/c/include/ICU4XLocaleFallbackConfig.h
new file mode 100644
index 0000000000..b40d115418
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbackConfig.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XLocaleFallbackConfig_H
+#define ICU4XLocaleFallbackConfig_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XLocaleFallbackPriority.h"
+#include "ICU4XLocaleFallbackSupplement.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleFallbackConfig {
+    ICU4XLocaleFallbackPriority priority;
+    DiplomatStringView extension_key;
+    ICU4XLocaleFallbackSupplement fallback_supplement;
+} ICU4XLocaleFallbackConfig;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLocaleFallbackPriority.h"
+#include "ICU4XLocaleFallbackSupplement.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLocaleFallbackConfig_destroy(ICU4XLocaleFallbackConfig* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbackIterator.h b/intl/icu_capi/c/include/ICU4XLocaleFallbackIterator.h
new file mode 100644
index 0000000000..e2dd7a1a3b
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbackIterator.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XLocaleFallbackIterator_H
+#define ICU4XLocaleFallbackIterator_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleFallbackIterator ICU4XLocaleFallbackIterator;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLocale.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XLocale* ICU4XLocaleFallbackIterator_get(const ICU4XLocaleFallbackIterator* self);
+
+void ICU4XLocaleFallbackIterator_step(ICU4XLocaleFallbackIterator* self);
+void ICU4XLocaleFallbackIterator_destroy(ICU4XLocaleFallbackIterator* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbackPriority.h b/intl/icu_capi/c/include/ICU4XLocaleFallbackPriority.h
new file mode 100644
index 0000000000..e4ab748065
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbackPriority.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XLocaleFallbackPriority_H
+#define ICU4XLocaleFallbackPriority_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLocaleFallbackPriority {
+  ICU4XLocaleFallbackPriority_Language = 0,
+  ICU4XLocaleFallbackPriority_Region = 1,
+  ICU4XLocaleFallbackPriority_Collation = 2,
+} ICU4XLocaleFallbackPriority;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLocaleFallbackPriority_destroy(ICU4XLocaleFallbackPriority* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbackSupplement.h b/intl/icu_capi/c/include/ICU4XLocaleFallbackSupplement.h
new file mode 100644
index 0000000000..952483c724
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbackSupplement.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XLocaleFallbackSupplement_H
+#define ICU4XLocaleFallbackSupplement_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XLocaleFallbackSupplement {
+  ICU4XLocaleFallbackSupplement_None = 0,
+  ICU4XLocaleFallbackSupplement_Collation = 1,
+} ICU4XLocaleFallbackSupplement;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XLocaleFallbackSupplement_destroy(ICU4XLocaleFallbackSupplement* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbacker.h b/intl/icu_capi/c/include/ICU4XLocaleFallbacker.h
new file mode 100644
index 0000000000..24efb0602f
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbacker.h
@@ -0,0 +1,37 @@
+#ifndef ICU4XLocaleFallbacker_H
+#define ICU4XLocaleFallbacker_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleFallbacker ICU4XLocaleFallbacker;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError.h"
+#include "ICU4XLocaleFallbackConfig.h"
+#include "diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError ICU4XLocaleFallbacker_create(const ICU4XDataProvider* provider);
+
+ICU4XLocaleFallbacker* ICU4XLocaleFallbacker_create_without_data();
+
+diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError ICU4XLocaleFallbacker_for_config(const ICU4XLocaleFallbacker* self, ICU4XLocaleFallbackConfig config);
+void ICU4XLocaleFallbacker_destroy(ICU4XLocaleFallbacker* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLocaleFallbackerWithConfig.h b/intl/icu_capi/c/include/ICU4XLocaleFallbackerWithConfig.h
new file mode 100644
index 0000000000..e8baa9563e
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLocaleFallbackerWithConfig.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XLocaleFallbackerWithConfig_H
+#define ICU4XLocaleFallbackerWithConfig_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLocaleFallbackerWithConfig ICU4XLocaleFallbackerWithConfig;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLocale.h"
+#include "ICU4XLocaleFallbackIterator.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XLocaleFallbackIterator* ICU4XLocaleFallbackerWithConfig_fallback_for_locale(const ICU4XLocaleFallbackerWithConfig* self, const ICU4XLocale* locale);
+void ICU4XLocaleFallbackerWithConfig_destroy(ICU4XLocaleFallbackerWithConfig* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XLogger.h b/intl/icu_capi/c/include/ICU4XLogger.h
new file mode 100644
index 0000000000..0aa1d0b1f9
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XLogger.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XLogger_H
+#define ICU4XLogger_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XLogger ICU4XLogger;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+bool ICU4XLogger_init_simple_logger();
+
+bool ICU4XLogger_init_console_logger();
+void ICU4XLogger_destroy(ICU4XLogger* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XMetazoneCalculator.h b/intl/icu_capi/c/include/ICU4XMetazoneCalculator.h
new file mode 100644
index 0000000000..9c66754e90
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XMetazoneCalculator.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XMetazoneCalculator_H
+#define ICU4XMetazoneCalculator_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XMetazoneCalculator ICU4XMetazoneCalculator;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError ICU4XMetazoneCalculator_create(const ICU4XDataProvider* provider);
+void ICU4XMetazoneCalculator_destroy(ICU4XMetazoneCalculator* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XOrdering.h b/intl/icu_capi/c/include/ICU4XOrdering.h
new file mode 100644
index 0000000000..2c1885f43e
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XOrdering.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XOrdering_H
+#define ICU4XOrdering_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XOrdering {
+  ICU4XOrdering_Less = -1,
+  ICU4XOrdering_Equal = 0,
+  ICU4XOrdering_Greater = 1,
+} ICU4XOrdering;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XOrdering_destroy(ICU4XOrdering* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XPluralCategories.h b/intl/icu_capi/c/include/ICU4XPluralCategories.h
new file mode 100644
index 0000000000..931ea2daa7
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XPluralCategories.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XPluralCategories_H
+#define ICU4XPluralCategories_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XPluralCategories {
+    bool zero;
+    bool one;
+    bool two;
+    bool few;
+    bool many;
+    bool other;
+} ICU4XPluralCategories;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XPluralCategories_destroy(ICU4XPluralCategories* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XPluralCategory.h b/intl/icu_capi/c/include/ICU4XPluralCategory.h
new file mode 100644
index 0000000000..543681c746
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XPluralCategory.h
@@ -0,0 +1,37 @@
+#ifndef ICU4XPluralCategory_H
+#define ICU4XPluralCategory_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XPluralCategory {
+  ICU4XPluralCategory_Zero = 0,
+  ICU4XPluralCategory_One = 1,
+  ICU4XPluralCategory_Two = 2,
+  ICU4XPluralCategory_Few = 3,
+  ICU4XPluralCategory_Many = 4,
+  ICU4XPluralCategory_Other = 5,
+} ICU4XPluralCategory;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_ICU4XPluralCategory_void.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_ICU4XPluralCategory_void ICU4XPluralCategory_get_for_cldr_string(const char* s_data, size_t s_len);
+void ICU4XPluralCategory_destroy(ICU4XPluralCategory* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XPluralOperands.h b/intl/icu_capi/c/include/ICU4XPluralOperands.h
new file mode 100644
index 0000000000..14d997555f
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XPluralOperands.h
@@ -0,0 +1,30 @@
+#ifndef ICU4XPluralOperands_H
+#define ICU4XPluralOperands_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XPluralOperands ICU4XPluralOperands;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XPluralOperands_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XPluralOperands_ICU4XError ICU4XPluralOperands_create_from_string(const char* s_data, size_t s_len);
+void ICU4XPluralOperands_destroy(ICU4XPluralOperands* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XPluralRules.h b/intl/icu_capi/c/include/ICU4XPluralRules.h
new file mode 100644
index 0000000000..0794a7ac8e
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XPluralRules.h
@@ -0,0 +1,41 @@
+#ifndef ICU4XPluralRules_H
+#define ICU4XPluralRules_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XPluralRules ICU4XPluralRules;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_box_ICU4XPluralRules_ICU4XError.h"
+#include "ICU4XPluralOperands.h"
+#include "ICU4XPluralCategory.h"
+#include "ICU4XPluralCategories.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XPluralRules_ICU4XError ICU4XPluralRules_create_cardinal(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XPluralRules_ICU4XError ICU4XPluralRules_create_ordinal(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+ICU4XPluralCategory ICU4XPluralRules_category_for(const ICU4XPluralRules* self, const ICU4XPluralOperands* op);
+
+ICU4XPluralCategories ICU4XPluralRules_categories(const ICU4XPluralRules* self);
+void ICU4XPluralRules_destroy(ICU4XPluralRules* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XPropertyValueNameToEnumMapper.h b/intl/icu_capi/c/include/ICU4XPropertyValueNameToEnumMapper.h
new file mode 100644
index 0000000000..54000ce338
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XPropertyValueNameToEnumMapper.h
@@ -0,0 +1,51 @@
+#ifndef ICU4XPropertyValueNameToEnumMapper_H
+#define ICU4XPropertyValueNameToEnumMapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XPropertyValueNameToEnumMapper ICU4XPropertyValueNameToEnumMapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int16_t ICU4XPropertyValueNameToEnumMapper_get_strict(const ICU4XPropertyValueNameToEnumMapper* self, const char* name_data, size_t name_len);
+
+int16_t ICU4XPropertyValueNameToEnumMapper_get_loose(const ICU4XPropertyValueNameToEnumMapper* self, const char* name_data, size_t name_len);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_general_category(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_bidi_class(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_east_asian_width(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_indic_syllabic_category(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_line_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_grapheme_cluster_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_word_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_sentence_break(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError ICU4XPropertyValueNameToEnumMapper_load_script(const ICU4XDataProvider* provider);
+void ICU4XPropertyValueNameToEnumMapper_destroy(ICU4XPropertyValueNameToEnumMapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XRegionDisplayNames.h b/intl/icu_capi/c/include/ICU4XRegionDisplayNames.h
new file mode 100644
index 0000000000..a78ec64865
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XRegionDisplayNames.h
@@ -0,0 +1,35 @@
+#ifndef ICU4XRegionDisplayNames_H
+#define ICU4XRegionDisplayNames_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XRegionDisplayNames ICU4XRegionDisplayNames;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError ICU4XRegionDisplayNames_create(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_void_ICU4XError ICU4XRegionDisplayNames_of(const ICU4XRegionDisplayNames* self, const char* region_data, size_t region_len, DiplomatWriteable* write);
+void ICU4XRegionDisplayNames_destroy(ICU4XRegionDisplayNames* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XReorderedIndexMap.h b/intl/icu_capi/c/include/ICU4XReorderedIndexMap.h
new file mode 100644
index 0000000000..f5507a7217
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XReorderedIndexMap.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XReorderedIndexMap_H
+#define ICU4XReorderedIndexMap_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XReorderedIndexMap ICU4XReorderedIndexMap;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+DiplomatUsizeView ICU4XReorderedIndexMap_as_slice(const ICU4XReorderedIndexMap* self);
+
+size_t ICU4XReorderedIndexMap_len(const ICU4XReorderedIndexMap* self);
+
+size_t ICU4XReorderedIndexMap_get(const ICU4XReorderedIndexMap* self, size_t index);
+void ICU4XReorderedIndexMap_destroy(ICU4XReorderedIndexMap* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XRoundingIncrement.h b/intl/icu_capi/c/include/ICU4XRoundingIncrement.h
new file mode 100644
index 0000000000..c4b0666bef
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XRoundingIncrement.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XRoundingIncrement_H
+#define ICU4XRoundingIncrement_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XRoundingIncrement {
+  ICU4XRoundingIncrement_MultiplesOf1 = 0,
+  ICU4XRoundingIncrement_MultiplesOf2 = 1,
+  ICU4XRoundingIncrement_MultiplesOf5 = 2,
+  ICU4XRoundingIncrement_MultiplesOf25 = 3,
+} ICU4XRoundingIncrement;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XRoundingIncrement_destroy(ICU4XRoundingIncrement* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XScriptExtensionsSet.h b/intl/icu_capi/c/include/ICU4XScriptExtensionsSet.h
new file mode 100644
index 0000000000..b4982dc22c
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XScriptExtensionsSet.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XScriptExtensionsSet_H
+#define ICU4XScriptExtensionsSet_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XScriptExtensionsSet ICU4XScriptExtensionsSet;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_uint16_t_void.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+bool ICU4XScriptExtensionsSet_contains(const ICU4XScriptExtensionsSet* self, uint16_t script);
+
+size_t ICU4XScriptExtensionsSet_count(const ICU4XScriptExtensionsSet* self);
+
+diplomat_result_uint16_t_void ICU4XScriptExtensionsSet_script_at(const ICU4XScriptExtensionsSet* self, size_t index);
+void ICU4XScriptExtensionsSet_destroy(ICU4XScriptExtensionsSet* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XScriptWithExtensions.h b/intl/icu_capi/c/include/ICU4XScriptWithExtensions.h
new file mode 100644
index 0000000000..df2dd53946
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XScriptWithExtensions.h
@@ -0,0 +1,41 @@
+#ifndef ICU4XScriptWithExtensions_H
+#define ICU4XScriptWithExtensions_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XScriptWithExtensions ICU4XScriptWithExtensions;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError.h"
+#include "ICU4XScriptWithExtensionsBorrowed.h"
+#include "CodePointRangeIterator.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError ICU4XScriptWithExtensions_create(const ICU4XDataProvider* provider);
+
+uint16_t ICU4XScriptWithExtensions_get_script_val(const ICU4XScriptWithExtensions* self, uint32_t code_point);
+
+bool ICU4XScriptWithExtensions_has_script(const ICU4XScriptWithExtensions* self, uint32_t code_point, uint16_t script);
+
+ICU4XScriptWithExtensionsBorrowed* ICU4XScriptWithExtensions_as_borrowed(const ICU4XScriptWithExtensions* self);
+
+CodePointRangeIterator* ICU4XScriptWithExtensions_iter_ranges_for_script(const ICU4XScriptWithExtensions* self, uint16_t script);
+void ICU4XScriptWithExtensions_destroy(ICU4XScriptWithExtensions* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XScriptWithExtensionsBorrowed.h b/intl/icu_capi/c/include/ICU4XScriptWithExtensionsBorrowed.h
new file mode 100644
index 0000000000..82faeec178
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XScriptWithExtensionsBorrowed.h
@@ -0,0 +1,37 @@
+#ifndef ICU4XScriptWithExtensionsBorrowed_H
+#define ICU4XScriptWithExtensionsBorrowed_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XScriptWithExtensionsBorrowed ICU4XScriptWithExtensionsBorrowed;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XScriptExtensionsSet.h"
+#include "ICU4XCodePointSetData.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+uint16_t ICU4XScriptWithExtensionsBorrowed_get_script_val(const ICU4XScriptWithExtensionsBorrowed* self, uint32_t code_point);
+
+ICU4XScriptExtensionsSet* ICU4XScriptWithExtensionsBorrowed_get_script_extensions_val(const ICU4XScriptWithExtensionsBorrowed* self, uint32_t code_point);
+
+bool ICU4XScriptWithExtensionsBorrowed_has_script(const ICU4XScriptWithExtensionsBorrowed* self, uint32_t code_point, uint16_t script);
+
+ICU4XCodePointSetData* ICU4XScriptWithExtensionsBorrowed_get_script_extensions_set(const ICU4XScriptWithExtensionsBorrowed* self, uint16_t script);
+void ICU4XScriptWithExtensionsBorrowed_destroy(ICU4XScriptWithExtensionsBorrowed* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XSegmenterWordType.h b/intl/icu_capi/c/include/ICU4XSegmenterWordType.h
new file mode 100644
index 0000000000..9f4f81cf10
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XSegmenterWordType.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XSegmenterWordType_H
+#define ICU4XSegmenterWordType_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XSegmenterWordType {
+  ICU4XSegmenterWordType_None = 0,
+  ICU4XSegmenterWordType_Number = 1,
+  ICU4XSegmenterWordType_Letter = 2,
+} ICU4XSegmenterWordType;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XSegmenterWordType_destroy(ICU4XSegmenterWordType* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorLatin1.h b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorLatin1.h
new file mode 100644
index 0000000000..6dd7b132dc
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorLatin1.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XSentenceBreakIteratorLatin1_H
+#define ICU4XSentenceBreakIteratorLatin1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XSentenceBreakIteratorLatin1 ICU4XSentenceBreakIteratorLatin1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XSentenceBreakIteratorLatin1_next(ICU4XSentenceBreakIteratorLatin1* self);
+void ICU4XSentenceBreakIteratorLatin1_destroy(ICU4XSentenceBreakIteratorLatin1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf16.h b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf16.h
new file mode 100644
index 0000000000..3ed0dc18c3
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf16.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XSentenceBreakIteratorUtf16_H
+#define ICU4XSentenceBreakIteratorUtf16_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XSentenceBreakIteratorUtf16 ICU4XSentenceBreakIteratorUtf16;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XSentenceBreakIteratorUtf16_next(ICU4XSentenceBreakIteratorUtf16* self);
+void ICU4XSentenceBreakIteratorUtf16_destroy(ICU4XSentenceBreakIteratorUtf16* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf8.h b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf8.h
new file mode 100644
index 0000000000..655cb67b6c
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XSentenceBreakIteratorUtf8.h
@@ -0,0 +1,29 @@
+#ifndef ICU4XSentenceBreakIteratorUtf8_H
+#define ICU4XSentenceBreakIteratorUtf8_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XSentenceBreakIteratorUtf8 ICU4XSentenceBreakIteratorUtf8;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XSentenceBreakIteratorUtf8_next(ICU4XSentenceBreakIteratorUtf8* self);
+void ICU4XSentenceBreakIteratorUtf8_destroy(ICU4XSentenceBreakIteratorUtf8* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XSentenceSegmenter.h b/intl/icu_capi/c/include/ICU4XSentenceSegmenter.h
new file mode 100644
index 0000000000..7701c9f042
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XSentenceSegmenter.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XSentenceSegmenter_H
+#define ICU4XSentenceSegmenter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XSentenceSegmenter ICU4XSentenceSegmenter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError.h"
+#include "ICU4XSentenceBreakIteratorUtf8.h"
+#include "ICU4XSentenceBreakIteratorUtf16.h"
+#include "ICU4XSentenceBreakIteratorLatin1.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError ICU4XSentenceSegmenter_create(const ICU4XDataProvider* provider);
+
+ICU4XSentenceBreakIteratorUtf8* ICU4XSentenceSegmenter_segment_utf8(const ICU4XSentenceSegmenter* self, const char* input_data, size_t input_len);
+
+ICU4XSentenceBreakIteratorUtf16* ICU4XSentenceSegmenter_segment_utf16(const ICU4XSentenceSegmenter* self, const uint16_t* input_data, size_t input_len);
+
+ICU4XSentenceBreakIteratorLatin1* ICU4XSentenceSegmenter_segment_latin1(const ICU4XSentenceSegmenter* self, const uint8_t* input_data, size_t input_len);
+void ICU4XSentenceSegmenter_destroy(ICU4XSentenceSegmenter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTime.h b/intl/icu_capi/c/include/ICU4XTime.h
new file mode 100644
index 0000000000..2f3a9967fa
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTime.h
@@ -0,0 +1,40 @@
+#ifndef ICU4XTime_H
+#define ICU4XTime_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XTime ICU4XTime;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "diplomat_result_box_ICU4XTime_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XTime_ICU4XError ICU4XTime_create(uint8_t hour, uint8_t minute, uint8_t second, uint32_t nanosecond);
+
+diplomat_result_box_ICU4XTime_ICU4XError ICU4XTime_create_midnight();
+
+uint8_t ICU4XTime_hour(const ICU4XTime* self);
+
+uint8_t ICU4XTime_minute(const ICU4XTime* self);
+
+uint8_t ICU4XTime_second(const ICU4XTime* self);
+
+uint32_t ICU4XTime_nanosecond(const ICU4XTime* self);
+void ICU4XTime_destroy(ICU4XTime* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTimeFormatter.h b/intl/icu_capi/c/include/ICU4XTimeFormatter.h
new file mode 100644
index 0000000000..d200881399
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTimeFormatter.h
@@ -0,0 +1,43 @@
+#ifndef ICU4XTimeFormatter_H
+#define ICU4XTimeFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XTimeFormatter ICU4XTimeFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XTimeLength.h"
+#include "diplomat_result_box_ICU4XTimeFormatter_ICU4XError.h"
+#include "ICU4XTime.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XDateTime.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XTimeFormatter_ICU4XError ICU4XTimeFormatter_create_with_length(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XTimeLength length);
+
+diplomat_result_void_ICU4XError ICU4XTimeFormatter_format_time(const ICU4XTimeFormatter* self, const ICU4XTime* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XTimeFormatter_format_datetime(const ICU4XTimeFormatter* self, const ICU4XDateTime* value, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XTimeFormatter_format_iso_datetime(const ICU4XTimeFormatter* self, const ICU4XIsoDateTime* value, DiplomatWriteable* write);
+void ICU4XTimeFormatter_destroy(ICU4XTimeFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTimeLength.h b/intl/icu_capi/c/include/ICU4XTimeLength.h
new file mode 100644
index 0000000000..6d98bc8ccb
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTimeLength.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XTimeLength_H
+#define ICU4XTimeLength_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XTimeLength {
+  ICU4XTimeLength_Full = 0,
+  ICU4XTimeLength_Long = 1,
+  ICU4XTimeLength_Medium = 2,
+  ICU4XTimeLength_Short = 3,
+} ICU4XTimeLength;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XTimeLength_destroy(ICU4XTimeLength* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTimeZoneFormatter.h b/intl/icu_capi/c/include/ICU4XTimeZoneFormatter.h
new file mode 100644
index 0000000000..5eb1299543
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTimeZoneFormatter.h
@@ -0,0 +1,53 @@
+#ifndef ICU4XTimeZoneFormatter_H
+#define ICU4XTimeZoneFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XTimeZoneFormatter ICU4XTimeZoneFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError.h"
+#include "ICU4XIsoTimeZoneOptions.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XCustomTimeZone.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError ICU4XTimeZoneFormatter_create_with_localized_gmt_fallback(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError ICU4XTimeZoneFormatter_create_with_iso_8601_fallback(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XIsoTimeZoneOptions options);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_generic_non_location_long(ICU4XTimeZoneFormatter* self, const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_generic_non_location_short(ICU4XTimeZoneFormatter* self, const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_specific_non_location_long(ICU4XTimeZoneFormatter* self, const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_specific_non_location_short(ICU4XTimeZoneFormatter* self, const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_generic_location_format(ICU4XTimeZoneFormatter* self, const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_include_localized_gmt_format(ICU4XTimeZoneFormatter* self);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_load_iso_8601_format(ICU4XTimeZoneFormatter* self, ICU4XIsoTimeZoneOptions options);
+
+diplomat_result_void_ICU4XError ICU4XTimeZoneFormatter_format_custom_time_zone(const ICU4XTimeZoneFormatter* self, const ICU4XCustomTimeZone* value, DiplomatWriteable* write);
+void ICU4XTimeZoneFormatter_destroy(ICU4XTimeZoneFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTitlecaseMapper.h b/intl/icu_capi/c/include/ICU4XTitlecaseMapper.h
new file mode 100644
index 0000000000..04debefbf9
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTitlecaseMapper.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XTitlecaseMapper_H
+#define ICU4XTitlecaseMapper_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XTitlecaseMapper ICU4XTitlecaseMapper;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError.h"
+#include "ICU4XLocale.h"
+#include "ICU4XTitlecaseOptionsV1.h"
+#include "diplomat_result_void_ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError ICU4XTitlecaseMapper_create(const ICU4XDataProvider* provider);
+
+diplomat_result_void_ICU4XError ICU4XTitlecaseMapper_titlecase_segment_v1(const ICU4XTitlecaseMapper* self, const char* s_data, size_t s_len, const ICU4XLocale* locale, ICU4XTitlecaseOptionsV1 options, DiplomatWriteable* write);
+void ICU4XTitlecaseMapper_destroy(ICU4XTitlecaseMapper* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTitlecaseOptionsV1.h b/intl/icu_capi/c/include/ICU4XTitlecaseOptionsV1.h
new file mode 100644
index 0000000000..a828188560
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTitlecaseOptionsV1.h
@@ -0,0 +1,36 @@
+#ifndef ICU4XTitlecaseOptionsV1_H
+#define ICU4XTitlecaseOptionsV1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XLeadingAdjustment.h"
+#include "ICU4XTrailingCase.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XTitlecaseOptionsV1 {
+    ICU4XLeadingAdjustment leading_adjustment;
+    ICU4XTrailingCase trailing_case;
+} ICU4XTitlecaseOptionsV1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XLeadingAdjustment.h"
+#include "ICU4XTrailingCase.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+ICU4XTitlecaseOptionsV1 ICU4XTitlecaseOptionsV1_default_options();
+void ICU4XTitlecaseOptionsV1_destroy(ICU4XTitlecaseOptionsV1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTrailingCase.h b/intl/icu_capi/c/include/ICU4XTrailingCase.h
new file mode 100644
index 0000000000..d8957e0088
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTrailingCase.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XTrailingCase_H
+#define ICU4XTrailingCase_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XTrailingCase {
+  ICU4XTrailingCase_Lower = 0,
+  ICU4XTrailingCase_Unchanged = 1,
+} ICU4XTrailingCase;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XTrailingCase_destroy(ICU4XTrailingCase* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XTransformResult.h b/intl/icu_capi/c/include/ICU4XTransformResult.h
new file mode 100644
index 0000000000..66b268e266
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XTransformResult.h
@@ -0,0 +1,31 @@
+#ifndef ICU4XTransformResult_H
+#define ICU4XTransformResult_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XTransformResult {
+  ICU4XTransformResult_Modified = 0,
+  ICU4XTransformResult_Unmodified = 1,
+} ICU4XTransformResult;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XTransformResult_destroy(ICU4XTransformResult* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XUnicodeSetData.h b/intl/icu_capi/c/include/ICU4XUnicodeSetData.h
new file mode 100644
index 0000000000..3e10e53097
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XUnicodeSetData.h
@@ -0,0 +1,48 @@
+#ifndef ICU4XUnicodeSetData_H
+#define ICU4XUnicodeSetData_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XUnicodeSetData ICU4XUnicodeSetData;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XUnicodeSetData_ICU4XError.h"
+#include "ICU4XLocale.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+bool ICU4XUnicodeSetData_contains(const ICU4XUnicodeSetData* self, const char* s_data, size_t s_len);
+
+bool ICU4XUnicodeSetData_contains_char(const ICU4XUnicodeSetData* self, char32_t cp);
+
+bool ICU4XUnicodeSetData_contains32(const ICU4XUnicodeSetData* self, uint32_t cp);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_basic_emoji(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_exemplars_main(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_exemplars_auxiliary(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_exemplars_punctuation(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_exemplars_numbers(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+diplomat_result_box_ICU4XUnicodeSetData_ICU4XError ICU4XUnicodeSetData_load_exemplars_index(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+void ICU4XUnicodeSetData_destroy(ICU4XUnicodeSetData* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWeekCalculator.h b/intl/icu_capi/c/include/ICU4XWeekCalculator.h
new file mode 100644
index 0000000000..02a52c6e87
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWeekCalculator.h
@@ -0,0 +1,39 @@
+#ifndef ICU4XWeekCalculator_H
+#define ICU4XWeekCalculator_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWeekCalculator ICU4XWeekCalculator;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "diplomat_result_box_ICU4XWeekCalculator_ICU4XError.h"
+#include "ICU4XIsoWeekday.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XWeekCalculator_ICU4XError ICU4XWeekCalculator_create(const ICU4XDataProvider* provider, const ICU4XLocale* locale);
+
+ICU4XWeekCalculator* ICU4XWeekCalculator_create_from_first_day_of_week_and_min_week_days(ICU4XIsoWeekday first_weekday, uint8_t min_week_days);
+
+ICU4XIsoWeekday ICU4XWeekCalculator_first_weekday(const ICU4XWeekCalculator* self);
+
+uint8_t ICU4XWeekCalculator_min_week_days(const ICU4XWeekCalculator* self);
+void ICU4XWeekCalculator_destroy(ICU4XWeekCalculator* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWeekOf.h b/intl/icu_capi/c/include/ICU4XWeekOf.h
new file mode 100644
index 0000000000..5441b943d4
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWeekOf.h
@@ -0,0 +1,33 @@
+#ifndef ICU4XWeekOf_H
+#define ICU4XWeekOf_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XWeekRelativeUnit.h"
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWeekOf {
+    uint16_t week;
+    ICU4XWeekRelativeUnit unit;
+} ICU4XWeekOf;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XWeekRelativeUnit.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XWeekOf_destroy(ICU4XWeekOf* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWeekRelativeUnit.h b/intl/icu_capi/c/include/ICU4XWeekRelativeUnit.h
new file mode 100644
index 0000000000..ee6802dc3b
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWeekRelativeUnit.h
@@ -0,0 +1,32 @@
+#ifndef ICU4XWeekRelativeUnit_H
+#define ICU4XWeekRelativeUnit_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef enum ICU4XWeekRelativeUnit {
+  ICU4XWeekRelativeUnit_Previous = 0,
+  ICU4XWeekRelativeUnit_Current = 1,
+  ICU4XWeekRelativeUnit_Next = 2,
+} ICU4XWeekRelativeUnit;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+void ICU4XWeekRelativeUnit_destroy(ICU4XWeekRelativeUnit* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWordBreakIteratorLatin1.h b/intl/icu_capi/c/include/ICU4XWordBreakIteratorLatin1.h
new file mode 100644
index 0000000000..112025bdf5
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWordBreakIteratorLatin1.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XWordBreakIteratorLatin1_H
+#define ICU4XWordBreakIteratorLatin1_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWordBreakIteratorLatin1 ICU4XWordBreakIteratorLatin1;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XSegmenterWordType.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XWordBreakIteratorLatin1_next(ICU4XWordBreakIteratorLatin1* self);
+
+ICU4XSegmenterWordType ICU4XWordBreakIteratorLatin1_word_type(const ICU4XWordBreakIteratorLatin1* self);
+
+bool ICU4XWordBreakIteratorLatin1_is_word_like(const ICU4XWordBreakIteratorLatin1* self);
+void ICU4XWordBreakIteratorLatin1_destroy(ICU4XWordBreakIteratorLatin1* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf16.h b/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf16.h
new file mode 100644
index 0000000000..676aea3cff
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf16.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XWordBreakIteratorUtf16_H
+#define ICU4XWordBreakIteratorUtf16_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWordBreakIteratorUtf16 ICU4XWordBreakIteratorUtf16;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XSegmenterWordType.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XWordBreakIteratorUtf16_next(ICU4XWordBreakIteratorUtf16* self);
+
+ICU4XSegmenterWordType ICU4XWordBreakIteratorUtf16_word_type(const ICU4XWordBreakIteratorUtf16* self);
+
+bool ICU4XWordBreakIteratorUtf16_is_word_like(const ICU4XWordBreakIteratorUtf16* self);
+void ICU4XWordBreakIteratorUtf16_destroy(ICU4XWordBreakIteratorUtf16* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf8.h b/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf8.h
new file mode 100644
index 0000000000..d8e98fb9b1
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWordBreakIteratorUtf8.h
@@ -0,0 +1,34 @@
+#ifndef ICU4XWordBreakIteratorUtf8_H
+#define ICU4XWordBreakIteratorUtf8_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWordBreakIteratorUtf8 ICU4XWordBreakIteratorUtf8;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XSegmenterWordType.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+int32_t ICU4XWordBreakIteratorUtf8_next(ICU4XWordBreakIteratorUtf8* self);
+
+ICU4XSegmenterWordType ICU4XWordBreakIteratorUtf8_word_type(const ICU4XWordBreakIteratorUtf8* self);
+
+bool ICU4XWordBreakIteratorUtf8_is_word_like(const ICU4XWordBreakIteratorUtf8* self);
+void ICU4XWordBreakIteratorUtf8_destroy(ICU4XWordBreakIteratorUtf8* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XWordSegmenter.h b/intl/icu_capi/c/include/ICU4XWordSegmenter.h
new file mode 100644
index 0000000000..5bef9437e0
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XWordSegmenter.h
@@ -0,0 +1,44 @@
+#ifndef ICU4XWordSegmenter_H
+#define ICU4XWordSegmenter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XWordSegmenter ICU4XWordSegmenter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "diplomat_result_box_ICU4XWordSegmenter_ICU4XError.h"
+#include "ICU4XWordBreakIteratorUtf8.h"
+#include "ICU4XWordBreakIteratorUtf16.h"
+#include "ICU4XWordBreakIteratorLatin1.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XWordSegmenter_ICU4XError ICU4XWordSegmenter_create_auto(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XWordSegmenter_ICU4XError ICU4XWordSegmenter_create_lstm(const ICU4XDataProvider* provider);
+
+diplomat_result_box_ICU4XWordSegmenter_ICU4XError ICU4XWordSegmenter_create_dictionary(const ICU4XDataProvider* provider);
+
+ICU4XWordBreakIteratorUtf8* ICU4XWordSegmenter_segment_utf8(const ICU4XWordSegmenter* self, const char* input_data, size_t input_len);
+
+ICU4XWordBreakIteratorUtf16* ICU4XWordSegmenter_segment_utf16(const ICU4XWordSegmenter* self, const uint16_t* input_data, size_t input_len);
+
+ICU4XWordBreakIteratorLatin1* ICU4XWordSegmenter_segment_latin1(const ICU4XWordSegmenter* self, const uint8_t* input_data, size_t input_len);
+void ICU4XWordSegmenter_destroy(ICU4XWordSegmenter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/ICU4XZonedDateTimeFormatter.h b/intl/icu_capi/c/include/ICU4XZonedDateTimeFormatter.h
new file mode 100644
index 0000000000..77b228a5a2
--- /dev/null
+++ b/intl/icu_capi/c/include/ICU4XZonedDateTimeFormatter.h
@@ -0,0 +1,45 @@
+#ifndef ICU4XZonedDateTimeFormatter_H
+#define ICU4XZonedDateTimeFormatter_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+#endif
+
+typedef struct ICU4XZonedDateTimeFormatter ICU4XZonedDateTimeFormatter;
+#ifdef __cplusplus
+} // namespace capi
+#endif
+#include "ICU4XDataProvider.h"
+#include "ICU4XLocale.h"
+#include "ICU4XDateLength.h"
+#include "ICU4XTimeLength.h"
+#include "diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError.h"
+#include "ICU4XIsoTimeZoneOptions.h"
+#include "ICU4XDateTime.h"
+#include "ICU4XCustomTimeZone.h"
+#include "diplomat_result_void_ICU4XError.h"
+#include "ICU4XIsoDateTime.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError ICU4XZonedDateTimeFormatter_create_with_lengths(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length);
+
+diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError ICU4XZonedDateTimeFormatter_create_with_lengths_and_iso_8601_time_zone_fallback(const ICU4XDataProvider* provider, const ICU4XLocale* locale, ICU4XDateLength date_length, ICU4XTimeLength time_length, ICU4XIsoTimeZoneOptions zone_options);
+
+diplomat_result_void_ICU4XError ICU4XZonedDateTimeFormatter_format_datetime_with_custom_time_zone(const ICU4XZonedDateTimeFormatter* self, const ICU4XDateTime* datetime, const ICU4XCustomTimeZone* time_zone, DiplomatWriteable* write);
+
+diplomat_result_void_ICU4XError ICU4XZonedDateTimeFormatter_format_iso_datetime_with_custom_time_zone(const ICU4XZonedDateTimeFormatter* self, const ICU4XIsoDateTime* datetime, const ICU4XCustomTimeZone* time_zone, DiplomatWriteable* write);
+void ICU4XZonedDateTimeFormatter_destroy(ICU4XZonedDateTimeFormatter* self);
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_ICU4XAnyCalendarKind_void.h b/intl/icu_capi/c/include/diplomat_result_ICU4XAnyCalendarKind_void.h
new file mode 100644
index 0000000000..f67f66ed4d
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_ICU4XAnyCalendarKind_void.h
@@ -0,0 +1,24 @@
+#ifndef diplomat_result_ICU4XAnyCalendarKind_void_H
+#define diplomat_result_ICU4XAnyCalendarKind_void_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XAnyCalendarKind.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_ICU4XAnyCalendarKind_void {
+    union {
+        ICU4XAnyCalendarKind ok;
+    };
+    bool is_ok;
+} diplomat_result_ICU4XAnyCalendarKind_void;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_ICU4XPluralCategory_void.h b/intl/icu_capi/c/include/diplomat_result_ICU4XPluralCategory_void.h
new file mode 100644
index 0000000000..b56ef60acb
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_ICU4XPluralCategory_void.h
@@ -0,0 +1,24 @@
+#ifndef diplomat_result_ICU4XPluralCategory_void_H
+#define diplomat_result_ICU4XPluralCategory_void_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XPluralCategory.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_ICU4XPluralCategory_void {
+    union {
+        ICU4XPluralCategory ok;
+    };
+    bool is_ok;
+} diplomat_result_ICU4XPluralCategory_void;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_ICU4XWeekOf_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_ICU4XWeekOf_ICU4XError.h
new file mode 100644
index 0000000000..4dee8f941f
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_ICU4XWeekOf_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_ICU4XWeekOf_ICU4XError_H
+#define diplomat_result_ICU4XWeekOf_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XWeekOf.h"
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_ICU4XWeekOf_ICU4XError {
+    union {
+        ICU4XWeekOf ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_ICU4XWeekOf_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_bool_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_bool_ICU4XError.h
new file mode 100644
index 0000000000..015930214d
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_bool_ICU4XError.h
@@ -0,0 +1,25 @@
+#ifndef diplomat_result_bool_ICU4XError_H
+#define diplomat_result_bool_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_bool_ICU4XError {
+    union {
+        bool ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_bool_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError.h
new file mode 100644
index 0000000000..0d18fe4076
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError_H
+#define diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XBcp47ToIanaMapper ICU4XBcp47ToIanaMapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError {
+    union {
+        ICU4XBcp47ToIanaMapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XBcp47ToIanaMapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XBidi_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XBidi_ICU4XError.h
new file mode 100644
index 0000000000..f1cd7ca6a3
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XBidi_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XBidi_ICU4XError_H
+#define diplomat_result_box_ICU4XBidi_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XBidi ICU4XBidi;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XBidi_ICU4XError {
+    union {
+        ICU4XBidi* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XBidi_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCalendar_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCalendar_ICU4XError.h
new file mode 100644
index 0000000000..bffa22c6b0
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCalendar_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCalendar_ICU4XError_H
+#define diplomat_result_box_ICU4XCalendar_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCalendar ICU4XCalendar;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCalendar_ICU4XError {
+    union {
+        ICU4XCalendar* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCalendar_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError.h
new file mode 100644
index 0000000000..2c05f79671
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError_H
+#define diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCanonicalCombiningClassMap ICU4XCanonicalCombiningClassMap;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError {
+    union {
+        ICU4XCanonicalCombiningClassMap* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCanonicalCombiningClassMap_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalComposition_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalComposition_ICU4XError.h
new file mode 100644
index 0000000000..66d0386ff8
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalComposition_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCanonicalComposition_ICU4XError_H
+#define diplomat_result_box_ICU4XCanonicalComposition_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCanonicalComposition ICU4XCanonicalComposition;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCanonicalComposition_ICU4XError {
+    union {
+        ICU4XCanonicalComposition* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCanonicalComposition_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError.h
new file mode 100644
index 0000000000..cf02637fef
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError_H
+#define diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCanonicalDecomposition ICU4XCanonicalDecomposition;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError {
+    union {
+        ICU4XCanonicalDecomposition* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCanonicalDecomposition_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapCloser_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapCloser_ICU4XError.h
new file mode 100644
index 0000000000..7b2a957399
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapCloser_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCaseMapCloser_ICU4XError_H
+#define diplomat_result_box_ICU4XCaseMapCloser_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCaseMapCloser ICU4XCaseMapCloser;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCaseMapCloser_ICU4XError {
+    union {
+        ICU4XCaseMapCloser* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCaseMapCloser_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapper_ICU4XError.h
new file mode 100644
index 0000000000..c6e03a748c
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCaseMapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCaseMapper_ICU4XError_H
+#define diplomat_result_box_ICU4XCaseMapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCaseMapper ICU4XCaseMapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCaseMapper_ICU4XError {
+    union {
+        ICU4XCaseMapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCaseMapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData16_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData16_ICU4XError.h
new file mode 100644
index 0000000000..fbe11daad2
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData16_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCodePointMapData16_ICU4XError_H
+#define diplomat_result_box_ICU4XCodePointMapData16_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCodePointMapData16 ICU4XCodePointMapData16;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCodePointMapData16_ICU4XError {
+    union {
+        ICU4XCodePointMapData16* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCodePointMapData16_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData8_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData8_ICU4XError.h
new file mode 100644
index 0000000000..2e203279e3
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointMapData8_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCodePointMapData8_ICU4XError_H
+#define diplomat_result_box_ICU4XCodePointMapData8_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCodePointMapData8 ICU4XCodePointMapData8;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCodePointMapData8_ICU4XError {
+    union {
+        ICU4XCodePointMapData8* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCodePointMapData8_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointSetData_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointSetData_ICU4XError.h
new file mode 100644
index 0000000000..e70e39ba61
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCodePointSetData_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCodePointSetData_ICU4XError_H
+#define diplomat_result_box_ICU4XCodePointSetData_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCodePointSetData ICU4XCodePointSetData;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCodePointSetData_ICU4XError {
+    union {
+        ICU4XCodePointSetData* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCodePointSetData_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCollator_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCollator_ICU4XError.h
new file mode 100644
index 0000000000..abb5c8a598
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCollator_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCollator_ICU4XError_H
+#define diplomat_result_box_ICU4XCollator_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCollator ICU4XCollator;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCollator_ICU4XError {
+    union {
+        ICU4XCollator* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCollator_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XComposingNormalizer_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XComposingNormalizer_ICU4XError.h
new file mode 100644
index 0000000000..d0c381ef03
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XComposingNormalizer_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XComposingNormalizer_ICU4XError_H
+#define diplomat_result_box_ICU4XComposingNormalizer_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XComposingNormalizer ICU4XComposingNormalizer;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XComposingNormalizer_ICU4XError {
+    union {
+        ICU4XComposingNormalizer* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XComposingNormalizer_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XCustomTimeZone_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCustomTimeZone_ICU4XError.h
new file mode 100644
index 0000000000..4709a89871
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XCustomTimeZone_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XCustomTimeZone_ICU4XError_H
+#define diplomat_result_box_ICU4XCustomTimeZone_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XCustomTimeZone ICU4XCustomTimeZone;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XCustomTimeZone_ICU4XError {
+    union {
+        ICU4XCustomTimeZone* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XCustomTimeZone_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataProvider_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataProvider_ICU4XError.h
new file mode 100644
index 0000000000..a5be844183
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataProvider_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDataProvider_ICU4XError_H
+#define diplomat_result_box_ICU4XDataProvider_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDataProvider ICU4XDataProvider;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDataProvider_ICU4XError {
+    union {
+        ICU4XDataProvider* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDataProvider_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataStruct_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataStruct_ICU4XError.h
new file mode 100644
index 0000000000..d8c1d33e21
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDataStruct_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDataStruct_ICU4XError_H
+#define diplomat_result_box_ICU4XDataStruct_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDataStruct ICU4XDataStruct;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDataStruct_ICU4XError {
+    union {
+        ICU4XDataStruct* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDataStruct_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateFormatter_ICU4XError.h
new file mode 100644
index 0000000000..b6d9671434
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDateFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XDateFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDateFormatter ICU4XDateFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDateFormatter_ICU4XError {
+    union {
+        ICU4XDateFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDateFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError.h
new file mode 100644
index 0000000000..855e74fe6c
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDateTimeFormatter ICU4XDateTimeFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError {
+    union {
+        ICU4XDateTimeFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDateTimeFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTime_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTime_ICU4XError.h
new file mode 100644
index 0000000000..2d4cb2fe48
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDateTime_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDateTime_ICU4XError_H
+#define diplomat_result_box_ICU4XDateTime_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDateTime ICU4XDateTime;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDateTime_ICU4XError {
+    union {
+        ICU4XDateTime* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDateTime_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDate_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDate_ICU4XError.h
new file mode 100644
index 0000000000..30461b264a
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDate_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDate_ICU4XError_H
+#define diplomat_result_box_ICU4XDate_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDate ICU4XDate;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDate_ICU4XError {
+    union {
+        ICU4XDate* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDate_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError.h
new file mode 100644
index 0000000000..c51d9907bc
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError_H
+#define diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XDecomposingNormalizer ICU4XDecomposingNormalizer;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError {
+    union {
+        ICU4XDecomposingNormalizer* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XDecomposingNormalizer_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError.h
new file mode 100644
index 0000000000..8ee245a093
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XFixedDecimalFormatter ICU4XFixedDecimalFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError {
+    union {
+        ICU4XFixedDecimalFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XFixedDecimalFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimal_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimal_ICU4XError.h
new file mode 100644
index 0000000000..f45cd78fb9
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XFixedDecimal_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XFixedDecimal_ICU4XError_H
+#define diplomat_result_box_ICU4XFixedDecimal_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XFixedDecimal ICU4XFixedDecimal;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XFixedDecimal_ICU4XError {
+    union {
+        ICU4XFixedDecimal* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XFixedDecimal_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError.h
new file mode 100644
index 0000000000..98ff137a9a
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError_H
+#define diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XGeneralCategoryNameToMaskMapper ICU4XGeneralCategoryNameToMaskMapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError {
+    union {
+        ICU4XGeneralCategoryNameToMaskMapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XGeneralCategoryNameToMaskMapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError.h
new file mode 100644
index 0000000000..d560b381a5
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError_H
+#define diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XGraphemeClusterSegmenter ICU4XGraphemeClusterSegmenter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError {
+    union {
+        ICU4XGraphemeClusterSegmenter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XGraphemeClusterSegmenter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError.h
new file mode 100644
index 0000000000..86b13be912
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XGregorianDateFormatter ICU4XGregorianDateFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError {
+    union {
+        ICU4XGregorianDateFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XGregorianDateFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError.h
new file mode 100644
index 0000000000..4393d9ffb0
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XGregorianDateTimeFormatter ICU4XGregorianDateTimeFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError {
+    union {
+        ICU4XGregorianDateTimeFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XGregorianDateTimeFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError.h
new file mode 100644
index 0000000000..270b38ba94
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XGregorianZonedDateTimeFormatter ICU4XGregorianZonedDateTimeFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError {
+    union {
+        ICU4XGregorianZonedDateTimeFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XGregorianZonedDateTimeFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError.h
new file mode 100644
index 0000000000..2e05730b0b
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError_H
+#define diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XIanaToBcp47Mapper ICU4XIanaToBcp47Mapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError {
+    union {
+        ICU4XIanaToBcp47Mapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XIanaToBcp47Mapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDateTime_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDateTime_ICU4XError.h
new file mode 100644
index 0000000000..8a55b47a68
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDateTime_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XIsoDateTime_ICU4XError_H
+#define diplomat_result_box_ICU4XIsoDateTime_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XIsoDateTime ICU4XIsoDateTime;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XIsoDateTime_ICU4XError {
+    union {
+        ICU4XIsoDateTime* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XIsoDateTime_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDate_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDate_ICU4XError.h
new file mode 100644
index 0000000000..8528d73b07
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XIsoDate_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XIsoDate_ICU4XError_H
+#define diplomat_result_box_ICU4XIsoDate_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XIsoDate ICU4XIsoDate;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XIsoDate_ICU4XError {
+    union {
+        ICU4XIsoDate* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XIsoDate_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLineSegmenter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLineSegmenter_ICU4XError.h
new file mode 100644
index 0000000000..004d3494ae
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLineSegmenter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLineSegmenter_ICU4XError_H
+#define diplomat_result_box_ICU4XLineSegmenter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLineSegmenter ICU4XLineSegmenter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLineSegmenter_ICU4XError {
+    union {
+        ICU4XLineSegmenter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLineSegmenter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XListFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XListFormatter_ICU4XError.h
new file mode 100644
index 0000000000..df40aa2dae
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XListFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XListFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XListFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XListFormatter ICU4XListFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XListFormatter_ICU4XError {
+    union {
+        ICU4XListFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XListFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError.h
new file mode 100644
index 0000000000..a49bb700ca
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleCanonicalizer ICU4XLocaleCanonicalizer;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError {
+    union {
+        ICU4XLocaleCanonicalizer* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleCanonicalizer_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError.h
new file mode 100644
index 0000000000..740f9d99fa
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleDirectionality ICU4XLocaleDirectionality;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError {
+    union {
+        ICU4XLocaleDirectionality* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleDirectionality_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError.h
new file mode 100644
index 0000000000..6b0f09b2a2
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleDisplayNamesFormatter ICU4XLocaleDisplayNamesFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError {
+    union {
+        ICU4XLocaleDisplayNamesFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleDisplayNamesFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleExpander_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleExpander_ICU4XError.h
new file mode 100644
index 0000000000..c7275e699c
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleExpander_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleExpander_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleExpander_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleExpander ICU4XLocaleExpander;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleExpander_ICU4XError {
+    union {
+        ICU4XLocaleExpander* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleExpander_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError.h
new file mode 100644
index 0000000000..0dc002718e
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleFallbackerWithConfig ICU4XLocaleFallbackerWithConfig;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError {
+    union {
+        ICU4XLocaleFallbackerWithConfig* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleFallbackerWithConfig_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError.h
new file mode 100644
index 0000000000..3427bf3e3a
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError_H
+#define diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocaleFallbacker ICU4XLocaleFallbacker;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError {
+    union {
+        ICU4XLocaleFallbacker* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocaleFallbacker_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocale_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocale_ICU4XError.h
new file mode 100644
index 0000000000..f5720b612f
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XLocale_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XLocale_ICU4XError_H
+#define diplomat_result_box_ICU4XLocale_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XLocale ICU4XLocale;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XLocale_ICU4XError {
+    union {
+        ICU4XLocale* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XLocale_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError.h
new file mode 100644
index 0000000000..ebd519e0b5
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError_H
+#define diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XMetazoneCalculator ICU4XMetazoneCalculator;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError {
+    union {
+        ICU4XMetazoneCalculator* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XMetazoneCalculator_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralOperands_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralOperands_ICU4XError.h
new file mode 100644
index 0000000000..7c068ba4b8
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralOperands_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XPluralOperands_ICU4XError_H
+#define diplomat_result_box_ICU4XPluralOperands_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XPluralOperands ICU4XPluralOperands;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XPluralOperands_ICU4XError {
+    union {
+        ICU4XPluralOperands* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XPluralOperands_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralRules_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralRules_ICU4XError.h
new file mode 100644
index 0000000000..4fa522b850
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPluralRules_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XPluralRules_ICU4XError_H
+#define diplomat_result_box_ICU4XPluralRules_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XPluralRules ICU4XPluralRules;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XPluralRules_ICU4XError {
+    union {
+        ICU4XPluralRules* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XPluralRules_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError.h
new file mode 100644
index 0000000000..047ef959b0
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError_H
+#define diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XPropertyValueNameToEnumMapper ICU4XPropertyValueNameToEnumMapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError {
+    union {
+        ICU4XPropertyValueNameToEnumMapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XPropertyValueNameToEnumMapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError.h
new file mode 100644
index 0000000000..fcf7e88a23
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError_H
+#define diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XRegionDisplayNames ICU4XRegionDisplayNames;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError {
+    union {
+        ICU4XRegionDisplayNames* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XRegionDisplayNames_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError.h
new file mode 100644
index 0000000000..bffd6161aa
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError_H
+#define diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XScriptWithExtensions ICU4XScriptWithExtensions;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError {
+    union {
+        ICU4XScriptWithExtensions* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XScriptWithExtensions_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError.h
new file mode 100644
index 0000000000..a8ab968fa9
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError_H
+#define diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XSentenceSegmenter ICU4XSentenceSegmenter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError {
+    union {
+        ICU4XSentenceSegmenter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XSentenceSegmenter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeFormatter_ICU4XError.h
new file mode 100644
index 0000000000..0e63cbbc2a
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XTimeFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XTimeFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XTimeFormatter ICU4XTimeFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XTimeFormatter_ICU4XError {
+    union {
+        ICU4XTimeFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XTimeFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError.h
new file mode 100644
index 0000000000..5f4851051e
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XTimeZoneFormatter ICU4XTimeZoneFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError {
+    union {
+        ICU4XTimeZoneFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XTimeZoneFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XTime_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTime_ICU4XError.h
new file mode 100644
index 0000000000..3e58b1e4da
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTime_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XTime_ICU4XError_H
+#define diplomat_result_box_ICU4XTime_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XTime ICU4XTime;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XTime_ICU4XError {
+    union {
+        ICU4XTime* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XTime_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError.h
new file mode 100644
index 0000000000..f8b017cfd4
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError_H
+#define diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XTitlecaseMapper ICU4XTitlecaseMapper;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError {
+    union {
+        ICU4XTitlecaseMapper* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XTitlecaseMapper_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XUnicodeSetData_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XUnicodeSetData_ICU4XError.h
new file mode 100644
index 0000000000..6dd14e82b6
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XUnicodeSetData_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XUnicodeSetData_ICU4XError_H
+#define diplomat_result_box_ICU4XUnicodeSetData_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XUnicodeSetData ICU4XUnicodeSetData;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XUnicodeSetData_ICU4XError {
+    union {
+        ICU4XUnicodeSetData* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XUnicodeSetData_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XWeekCalculator_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XWeekCalculator_ICU4XError.h
new file mode 100644
index 0000000000..1f547fd383
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XWeekCalculator_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XWeekCalculator_ICU4XError_H
+#define diplomat_result_box_ICU4XWeekCalculator_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XWeekCalculator ICU4XWeekCalculator;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XWeekCalculator_ICU4XError {
+    union {
+        ICU4XWeekCalculator* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XWeekCalculator_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XWordSegmenter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XWordSegmenter_ICU4XError.h
new file mode 100644
index 0000000000..e41c59b661
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XWordSegmenter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XWordSegmenter_ICU4XError_H
+#define diplomat_result_box_ICU4XWordSegmenter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XWordSegmenter ICU4XWordSegmenter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XWordSegmenter_ICU4XError {
+    union {
+        ICU4XWordSegmenter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XWordSegmenter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError.h
new file mode 100644
index 0000000000..52a0ab4462
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError.h
@@ -0,0 +1,26 @@
+#ifndef diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError_H
+#define diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+typedef struct ICU4XZonedDateTimeFormatter ICU4XZonedDateTimeFormatter;
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError {
+    union {
+        ICU4XZonedDateTimeFormatter* ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_box_ICU4XZonedDateTimeFormatter_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_int32_t_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_int32_t_ICU4XError.h
new file mode 100644
index 0000000000..adbe148dd1
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_int32_t_ICU4XError.h
@@ -0,0 +1,25 @@
+#ifndef diplomat_result_int32_t_ICU4XError_H
+#define diplomat_result_int32_t_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_int32_t_ICU4XError {
+    union {
+        int32_t ok;
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_int32_t_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_uint16_t_void.h b/intl/icu_capi/c/include/diplomat_result_uint16_t_void.h
new file mode 100644
index 0000000000..3adeb5f36d
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_uint16_t_void.h
@@ -0,0 +1,23 @@
+#ifndef diplomat_result_uint16_t_void_H
+#define diplomat_result_uint16_t_void_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_uint16_t_void {
+    union {
+        uint16_t ok;
+    };
+    bool is_ok;
+} diplomat_result_uint16_t_void;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_void_ICU4XError.h b/intl/icu_capi/c/include/diplomat_result_void_ICU4XError.h
new file mode 100644
index 0000000000..f092491e34
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_void_ICU4XError.h
@@ -0,0 +1,24 @@
+#ifndef diplomat_result_void_ICU4XError_H
+#define diplomat_result_void_ICU4XError_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#include "ICU4XError.h"
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_void_ICU4XError {
+    union {
+        ICU4XError err;
+    };
+    bool is_ok;
+} diplomat_result_void_ICU4XError;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_result_void_void.h b/intl/icu_capi/c/include/diplomat_result_void_void.h
new file mode 100644
index 0000000000..2d5cc704e5
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_result_void_void.h
@@ -0,0 +1,20 @@
+#ifndef diplomat_result_void_void_H
+#define diplomat_result_void_void_H
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "diplomat_runtime.h"
+
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+typedef struct diplomat_result_void_void {
+    bool is_ok;
+} diplomat_result_void_void;
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+#endif
diff --git a/intl/icu_capi/c/include/diplomat_runtime.h b/intl/icu_capi/c/include/diplomat_runtime.h
new file mode 100644
index 0000000000..de0f9c76fe
--- /dev/null
+++ b/intl/icu_capi/c/include/diplomat_runtime.h
@@ -0,0 +1,70 @@
+#ifndef DIPLOMAT_RUNTIME_C_H
+#define DIPLOMAT_RUNTIME_C_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+// uchar.h doesn't always exist, but char32_t is always available
+// in C++ anyway
+#ifndef __cplusplus
+#ifdef __APPLE__
+#include <stdint.h>
+typedef uint16_t char16_t;
+typedef uint32_t char32_t;
+#else
+#include <uchar.h>
+#endif
+#endif
+
+
+#ifdef __cplusplus
+namespace capi {
+extern "C" {
+#endif
+
+typedef struct DiplomatWriteable {
+    void* context;
+    char* buf;
+    size_t len;
+    size_t cap;
+    void (*flush)(struct DiplomatWriteable*);
+    bool (*grow)(struct DiplomatWriteable*, size_t);
+} DiplomatWriteable;
+
+DiplomatWriteable diplomat_simple_writeable(char* buf, size_t buf_size);
+
+typedef struct DiplomatStringView {
+    const char* data;
+    size_t len;
+} DiplomatStringView;
+
+#define MAKE_SLICE_VIEW(name, c_ty) \
+    typedef struct Diplomat##name##View { \
+        const c_ty* data; \
+        size_t len; \
+    } Diplomat##name##View;
+
+MAKE_SLICE_VIEW(I8, int8_t)
+MAKE_SLICE_VIEW(U8, uint8_t)
+MAKE_SLICE_VIEW(I16, int16_t)
+MAKE_SLICE_VIEW(U16, uint16_t)
+MAKE_SLICE_VIEW(I32, int32_t)
+MAKE_SLICE_VIEW(U32, uint32_t)
+MAKE_SLICE_VIEW(I64, int64_t)
+MAKE_SLICE_VIEW(U64, uint64_t)
+MAKE_SLICE_VIEW(Isize, intptr_t)
+MAKE_SLICE_VIEW(Usize, size_t)
+MAKE_SLICE_VIEW(F32, float)
+MAKE_SLICE_VIEW(F64, double)
+MAKE_SLICE_VIEW(Bool, bool)
+MAKE_SLICE_VIEW(Char, char32_t)
+
+
+#ifdef __cplusplus
+} // extern "C"
+} // namespace capi
+#endif
+
+#endif