+U_CFUNC UBool U_EXPORT2
+ucase_addStringCaseClosure(const UChar *s, int32_t length, const USetAdder *sa);
+
+#ifdef __cplusplus
+U_NAMESPACE_BEGIN
+
+/**
+ * Iterator over characters with more than one code point in the full default Case_Folding.
+ */
+class U_COMMON_API FullCaseFoldingIterator {
+public:
+ /** Constructor. */
+ FullCaseFoldingIterator();
+ /**
+ * Returns the next (cp, full) pair where "full" is cp's full default Case_Folding.
+ * Returns a negative cp value at the end of the iteration.
+ */
+ UChar32 next(UnicodeString &full);
+private:
+ FullCaseFoldingIterator(const FullCaseFoldingIterator &); // no copy
+ FullCaseFoldingIterator &operator=(const FullCaseFoldingIterator &); // no assignment
+
+ const UChar *unfold;
+ int32_t unfoldRows;
+ int32_t unfoldRowWidth;
+ int32_t unfoldStringWidth;
+ int32_t currentRow;
+ int32_t rowCpIndex;
+};
+
+/**
+ * Fast case mapping data for ASCII/Latin.
+ * Linear arrays of delta bytes: 0=no mapping; EXC=exception.
+ * Deltas must not cross the ASCII boundary, or else they cannot be easily used
+ * in simple UTF-8 code.
+ */
+namespace LatinCase {
+
+/** Case mapping/folding data for code points up to U+017F. */
+constexpr UChar LIMIT = 0x180;
+/** U+017F case-folds and uppercases crossing the ASCII boundary. */
+constexpr UChar LONG_S = 0x17f;
+/** Exception: Complex mapping, or too-large delta. */
+constexpr int8_t EXC = -0x80;
+
+/** Deltas for lowercasing for most locales, and default case folding. */
+extern const int8_t TO_LOWER_NORMAL[LIMIT];
+/** Deltas for lowercasing for tr/az/lt, and Turkic case folding. */
+extern const int8_t TO_LOWER_TR_LT[LIMIT];
+
+/** Deltas for uppercasing for most locales. */
+extern const int8_t TO_UPPER_NORMAL[LIMIT];
+/** Deltas for uppercasing for tr/az. */
+extern const int8_t TO_UPPER_TR[LIMIT];
+
+} // namespace LatinCase
+
+U_NAMESPACE_END
+#endif