1 files changed, 99 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/erarules.h b/intl/icu/source/i18n/erarules.h
new file mode 100644
index 0000000000..74b7862da4
--- /dev/null
+++ b/intl/icu/source/i18n/erarules.h
@@ -0,0 +1,99 @@
+// © 2018 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+
+#ifndef ERARULES_H_
+#define ERARULES_H_
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/localpointer.h"
+#include "unicode/uobject.h"
+#include "cmemory.h"
+
+U_NAMESPACE_BEGIN
+
+// Export an explicit template instantiation of LocalMemory used as a data member of EraRules.
+// When building DLLs for Windows this is required even though no direct access leaks out of the i18n library.
+// See digitlst.h, pluralaffix.h, datefmt.h, and others for similar examples.
+#if U_PF_WINDOWS <= U_PLATFORM && U_PLATFORM <= U_PF_CYGWIN
+#if defined(_MSC_VER)
+// Ignore warning 4661 as LocalPointerBase does not use operator== or operator!=
+#pragma warning(push)
+#pragma warning(disable: 4661)
+#endif
+template class U_I18N_API LocalPointerBase<int32_t>;
+template class U_I18N_API LocalMemory<int32_t>;
+#if defined(_MSC_VER)
+#pragma warning(pop)
+#endif
+#endif
+
+class U_I18N_API EraRules : public UMemory {
+public:
+    ~EraRules();
+
+    static EraRules* createInstance(const char *calType, UBool includeTentativeEra, UErrorCode& status);
+
+    /**
+     * Gets number of effective eras
+     * @return  number of effective eras
+     */
+    inline int32_t getNumberOfEras() const {
+        return numEras;
+    }
+
+    /**
+     * Gets start date of an era
+     * @param eraIdx    Era index
+     * @param fields    Receives date fields. The result includes values of year, month,
+     *                  day of month in this order. When an era has no start date, the result
+     *                  will be January 1st in year whose value is minimum integer.
+     * @param status    Receives status.
+     */
+    void getStartDate(int32_t eraIdx, int32_t (&fields)[3], UErrorCode& status) const;
+
+    /**
+     * Gets start year of an era
+     * @param eraIdx    Era index
+     * @param status    Receives status.
+     * @return The first year of an era. When a era has no start date, minimum int32
+     *          value is returned.
+     */
+    int32_t getStartYear(int32_t eraIdx, UErrorCode& status) const;
+
+    /**
+     * Returns era index for the specified year/month/day.
+     * @param year  Year
+     * @param month Month (1-base)
+     * @param day   Day of month
+     * @param status    Receives status
+     * @return  era index (or 0, when the specified date is before the first era)
+     */
+    int32_t getEraIndex(int32_t year, int32_t month, int32_t day, UErrorCode& status) const;
+
+    /**
+     * Gets the current era index. This is calculated only once for an instance of
+     * EraRules. The current era calculation is based on the default time zone at
+     * the time of instantiation.
+     *
+     * @return era index of current era (or 0, when current date is before the first era)
+     */
+    inline int32_t getCurrentEraIndex() const {
+        return currentEra;
+    }
+
+private:
+    EraRules(LocalMemory<int32_t>& eraStartDates, int32_t numEra);
+
+    void initCurrentEra();
+
+    LocalMemory<int32_t> startDates;
+    int32_t numEras;
+    int32_t currentEra;
+};
+
+U_NAMESPACE_END
+#endif /* #if !UCONFIG_NO_FORMATTING */
+#endif /* ERARULES_H_ */