ICU-22954 toU16StringView not header-only

icu4c/source/common/unicode/char16ptr.h

@@ -36,6 +36,7 @@
 #   define U_ALIASING_BARRIER(ptr)
 #endif
 
+// ICU DLL-exported
 #if U_SHOW_CPLUSPLUS_API
 
 U_NAMESPACE_BEGIN
@@ -259,10 +260,25 @@ U_NAMESPACE_END
 
 #endif  // U_SHOW_CPLUSPLUS_API
 
+// Usable in header-only definitions
 #if U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API
 
 namespace U_ICU_NAMESPACE_OR_INTERNAL {
 
+#ifndef U_FORCE_HIDE_INTERNAL_API
+/** @internal */
+inline const char16_t *uprv_char16PtrFromUChar(const UChar *p) {
+#if U_SHOW_CPLUSPLUS_API
+    return ConstChar16Ptr(p).get();
+#else
+#ifdef U_ALIASING_BARRIER
+    U_ALIASING_BARRIER(p);
+#endif
+    return reinterpret_cast<const char16_t *>(p);
+#endif
+}
+#endif
+
 /**
  * Converts from const char16_t * to const UChar *.
  * Includes an aliasing barrier if available.
@@ -319,19 +335,16 @@ inline OldUChar *toOldUCharPtr(char16_t *p) {
     return reinterpret_cast<OldUChar *>(p);
 }
 
-#ifndef U_FORCE_HIDE_INTERNAL_API
-/** @internal */
-inline const char16_t *uprv_char16PtrFromUChar(const UChar *p) {
+}  // U_ICU_NAMESPACE_OR_INTERNAL
+
+#endif  // U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API
+
+// ICU DLL-exported
 #if U_SHOW_CPLUSPLUS_API
-    return ConstChar16Ptr(p).get();
-#else
-#ifdef U_ALIASING_BARRIER
-    U_ALIASING_BARRIER(p);
-#endif
-    return reinterpret_cast<const char16_t *>(p);
-#endif
-}
 
+U_NAMESPACE_BEGIN
+
+#ifndef U_FORCE_HIDE_INTERNAL_API
 /**
  * Is T convertible to a std::u16string_view or some other 16-bit string view?
  * @internal
@@ -347,22 +360,20 @@ constexpr bool ConvertibleToU16StringView =
 #endif
     ;
 
-// The following use ConstChar16Ptr.
-#if U_SHOW_CPLUSPLUS_API
-
+namespace internal {
 /**
  * Pass-through overload.
  * @internal
  */
-inline std::u16string_view uprv_toU16StringView(std::u16string_view sv) { return sv; }
+inline std::u16string_view toU16StringView(std::u16string_view sv) { return sv; }
 
 #if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
 /**
  * Basically undefined behavior but sometimes necessary conversion
  * from std::basic_string_view<uint16_t> to std::u16string_view.
  * @internal
  */
-inline std::u16string_view uprv_toU16StringView(std::basic_string_view<uint16_t> sv) {
+inline std::u16string_view toU16StringView(std::basic_string_view<uint16_t> sv) {
     return { ConstChar16Ptr(sv.data()), sv.length() };
 }
 #endif
@@ -373,7 +384,7 @@ inline std::u16string_view uprv_toU16StringView(std::basic_string_view<uint16_t>
  * from std::wstring_view to std::u16string_view.
  * @internal
  */
-inline std::u16string_view uprv_toU16StringView(std::wstring_view sv) {
+inline std::u16string_view toU16StringView(std::wstring_view sv) {
     return { ConstChar16Ptr(sv.data()), sv.length() };
 }
 #endif
@@ -384,8 +395,8 @@ inline std::u16string_view uprv_toU16StringView(std::wstring_view sv) {
  */
 template <typename T,
           typename = typename std::enable_if_t<!std::is_pointer_v<std::remove_reference_t<T>>>>
-inline std::u16string_view uprv_toU16StringViewNullable(const T& text) {
-    return uprv_toU16StringView(text);
+inline std::u16string_view toU16StringViewNullable(const T& text) {
+    return toU16StringView(text);
 }
 
 /**
@@ -395,17 +406,16 @@ inline std::u16string_view uprv_toU16StringViewNullable(const T& text) {
 template <typename T,
           typename = typename std::enable_if_t<std::is_pointer_v<std::remove_reference_t<T>>>,
           typename = void>
-inline std::u16string_view uprv_toU16StringViewNullable(const T& text) {
+inline std::u16string_view toU16StringViewNullable(const T& text) {
     if (text == nullptr) return {};  // For backward compatibility.
-    return uprv_toU16StringView(text);
+    return toU16StringView(text);
 }
 
-#endif  // U_SHOW_CPLUSPLUS_API
-
+}  // internal
 #endif  // U_FORCE_HIDE_INTERNAL_API
 
-}  // U_ICU_NAMESPACE_OR_INTERNAL
+U_NAMESPACE_END
 
-#endif  // U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API
+#endif  // U_SHOW_CPLUSPLUS_API
 
 #endif  // __CHAR16PTR_H__

icu4c/source/common/unicode/unistr.h

@@ -345,7 +345,7 @@ class U_COMMON_API UnicodeString : public Replaceable
    */
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   inline bool operator==(const S &text) const {
-    std::u16string_view sv(uprv_toU16StringView(text));
+    std::u16string_view sv(internal::toU16StringView(text));
     uint32_t len;  // unsigned to avoid a compiler warning
     return !isBogus() && (len = length()) == sv.length() && doEquals(sv.data(), len);
   }
@@ -1959,7 +1959,7 @@ class U_COMMON_API UnicodeString : public Replaceable
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   inline UnicodeString &operator=(const S &src) {
     unBogus();
-    return doReplace(0, length(), uprv_toU16StringView(src));
+    return doReplace(0, length(), internal::toU16StringView(src));
   }
 #endif  // U_HIDE_DRAFT_API
 
@@ -2225,7 +2225,7 @@ class U_COMMON_API UnicodeString : public Replaceable
    */
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   inline UnicodeString& operator+=(const S &src) {
-    return doAppend(uprv_toU16StringView(src));
+    return doAppend(internal::toU16StringView(src));
   }
 #endif  // U_HIDE_DRAFT_API
 
@@ -2298,7 +2298,7 @@ class U_COMMON_API UnicodeString : public Replaceable
    */
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   inline UnicodeString& append(const S &src) {
-    return doAppend(uprv_toU16StringView(src));
+    return doAppend(internal::toU16StringView(src));
   }
 #endif  // U_HIDE_DRAFT_API
 
@@ -3273,7 +3273,7 @@ class U_COMMON_API UnicodeString : public Replaceable
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   UNISTR_FROM_STRING_EXPLICIT UnicodeString(const S &text) {
     fUnion.fFields.fLengthAndFlags = kShortString;
-    doAppend(uprv_toU16StringViewNullable(text));
+    doAppend(internal::toU16StringViewNullable(text));
   }
 #endif  // U_HIDE_DRAFT_API
 
@@ -3598,7 +3598,7 @@ class U_COMMON_API UnicodeString : public Replaceable
    */
   template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
   static inline UnicodeString readOnlyAlias(const S &text) {
-    return readOnlyAliasFromU16StringView(uprv_toU16StringView(text));
+    return readOnlyAliasFromU16StringView(internal::toU16StringView(text));
   }
 
   /**
@@ -4115,7 +4115,7 @@ operator+ (const UnicodeString &s1, const UnicodeString &s2);
  */
 template<typename S, typename = std::enable_if_t<ConvertibleToU16StringView<S>>>
 inline UnicodeString operator+(const UnicodeString &s1, const S &s2) {
-  return unistr_internalConcat(s1, uprv_toU16StringView(s2));
+  return unistr_internalConcat(s1, internal::toU16StringView(s2));
 }
 #endif  // U_HIDE_DRAFT_API