2 files changed, 101 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/strings/str_join.h b/third_party/libwebrtc/rtc_base/strings/str_join.h
new file mode 100644
index 0000000000..762e63ae2a
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/strings/str_join.h
@@ -0,0 +1,56 @@
+/*
+ *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef RTC_BASE_STRINGS_STR_JOIN_H_
+#define RTC_BASE_STRINGS_STR_JOIN_H_
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace webrtc {
+
+template <typename Range>
+std::string StrJoin(const Range& seq, absl::string_view delimiter) {
+  rtc::StringBuilder sb;
+  int idx = 0;
+
+  for (const typename Range::value_type& elem : seq) {
+    if (idx > 0) {
+      sb << delimiter;
+    }
+    sb << elem;
+
+    ++idx;
+  }
+  return sb.Release();
+}
+
+template <typename Range, typename Functor>
+std::string StrJoin(const Range& seq,
+                    absl::string_view delimiter,
+                    const Functor& fn) {
+  rtc::StringBuilder sb;
+  int idx = 0;
+
+  for (const typename Range::value_type& elem : seq) {
+    if (idx > 0) {
+      sb << delimiter;
+    }
+    fn(sb, elem);
+
+    ++idx;
+  }
+  return sb.Release();
+}
+
+}  // namespace webrtc
+
+#endif  // RTC_BASE_STRINGS_STR_JOIN_H_
diff --git a/third_party/libwebrtc/rtc_base/strings/str_join_unittest.cc b/third_party/libwebrtc/rtc_base/strings/str_join_unittest.cc
new file mode 100644
index 0000000000..a4ac02125f
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/strings/str_join_unittest.cc
@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "rtc_base/strings/str_join.h"
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+TEST(StrJoinTest, CanJoinStringsFromVector) {
+  std::vector<std::string> strings = {"Hello", "World"};
+  std::string s = StrJoin(strings, " ");
+  EXPECT_EQ(s, "Hello World");
+}
+
+TEST(StrJoinTest, CanJoinNumbersFromArray) {
+  std::array<int, 3> numbers = {1, 2, 3};
+  std::string s = StrJoin(numbers, ",");
+  EXPECT_EQ(s, "1,2,3");
+}
+
+TEST(StrJoinTest, CanFormatElementsWhileJoining) {
+  std::vector<std::pair<std::string, std::string>> pairs = {
+      {"hello", "world"}, {"foo", "bar"}, {"fum", "gazonk"}};
+  std::string s = StrJoin(pairs, ",",
+                          [&](rtc::StringBuilder& sb,
+                              const std::pair<std::string, std::string>& p) {
+                            sb << p.first << "=" << p.second;
+                          });
+  EXPECT_EQ(s, "hello=world,foo=bar,fum=gazonk");
+}
+
+}  // namespace
+}  // namespace webrtc