libstdc++: Always define typedefs and hash functions for wide strings [PR 98725]

The wstring and wstring_view typedefs should be enabled even if <wchar.h> isn't supported, because char_traits<wchar_t> works unconditionally. Similarly, the std::hash specializations for wide strings do not depend on <wchar.h> support. Although the primary template works OK for std::char_traits<wchar_t> in the absence of <wchar.h> support, this patch still defines it as an explicit specialization for compatibility with declarations that expect it to be specialized. The explicit specialization just uses the same __gnu_cxx::char_traits base class as the primary template. libstdc++-v3/ChangeLog: PR libstdc++/98725 * include/bits/char_traits.h (char_traits<wchar_t>): Define explicit specialization unconditionally. * include/bits/basic_string.h (hash<wstring>): Define unconditionally. Do not check _GLIBCXX_USE_WCHAR_T. * include/bits/stringfwd.h (wstring): Likewise. * include/debug/string (wstring): Likewise. * include/experimental/string_view (experimental::wstring_view) (hash<experimental::wstring_view>): Likewise. * include/std/string (pmr::wstring, hash<pmr::wstring>): Likewise. * include/std/string_view (wstring_view, hash<wstring_view>): Likewise.
2021-10-08 14:24:18 +01:00 · 2021-10-08 14:24:18 +01:00 · 0afb9ebaab
parent cfeff094e6
commit 0afb9ebaab
7 changed files with 5 additions and 27 deletions
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@ -3954,7 +3954,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    struct __is_fast_hash<hash<string>> : std::false_type
    { };

-#ifdef _GLIBCXX_USE_WCHAR_T
  /// std::hash specialization for wstring.
  template<>
    struct hash<wstring>
@ -3969,7 +3968,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  template<>
    struct __is_fast_hash<hash<wstring>> : std::false_type
    { };
-#endif
 #endif /* _GLIBCXX_COMPATIBILITY_CXX0X */

 #ifdef _GLIBCXX_USE_CHAR8_T
@ -4034,12 +4032,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    operator""s(const char* __str, size_t __len)
    { return basic_string<char>{__str, __len}; }

-#ifdef _GLIBCXX_USE_WCHAR_T
    _GLIBCXX_DEFAULT_ABI_TAG
    inline basic_string<wchar_t>
    operator""s(const wchar_t* __str, size_t __len)
    { return basic_string<wchar_t>{__str, __len}; }
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
    _GLIBCXX_DEFAULT_ABI_TAG
--- a/libstdc++-v3/include/bits/char_traits.h
+++ b/libstdc++-v3/include/bits/char_traits.h
@ -256,7 +256,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   *  for advice on how to make use of this class for @a unusual character
   *  types. Also, check out include/ext/pod_char_traits.h.
  */
-  template<class _CharT>
+  template<typename _CharT>
    struct char_traits : public __gnu_cxx::char_traits<_CharT>
    { };

@ -507,6 +507,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return eq_int_type(__c, eof()) ? 0 : __c; }
  };
+#else // _GLIBCXX_USE_WCHAR_T
+  template<>
+    struct char_traits<wchar_t> : public __gnu_cxx::char_traits<wchar_t>
+    { };
 #endif //_GLIBCXX_USE_WCHAR_T

 #ifdef _GLIBCXX_USE_CHAR8_T
--- a/libstdc++-v3/include/bits/stringfwd.h
+++ b/libstdc++-v3/include/bits/stringfwd.h
@ -54,9 +54,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION

  template<> struct char_traits<char>;

-#ifdef _GLIBCXX_USE_WCHAR_T
  template<> struct char_traits<wchar_t>;
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
  template<> struct char_traits<char8_t>;
@ -78,10 +76,8 @@ _GLIBCXX_END_NAMESPACE_CXX11
  /// A string of @c char
  typedef basic_string<char>    string;   

-#ifdef _GLIBCXX_USE_WCHAR_T
  /// A string of @c wchar_t
  typedef basic_string<wchar_t> wstring;   
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
  /// A string of @c char8_t
--- a/libstdc++-v3/include/debug/string
+++ b/libstdc++-v3/include/debug/string
@ -1298,9 +1298,7 @@ namespace __gnu_debug

  typedef basic_string<char>    string;

-#ifdef _GLIBCXX_USE_WCHAR_T
  typedef basic_string<wchar_t> wstring;
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
  /// A string of @c char8_t
--- a/libstdc++-v3/include/experimental/string_view
+++ b/libstdc++-v3/include/experimental/string_view
@ -564,9 +564,7 @@ inline namespace fundamentals_v1
  // basic_string_view typedef names

  using string_view = basic_string_view<char>;
-#ifdef _GLIBCXX_USE_WCHAR_T
  using wstring_view = basic_string_view<wchar_t>;
-#endif
 #ifdef _GLIBCXX_USE_CHAR8_T
  using u8string_view = basic_string_view<char8_t>;
 #endif
@ -593,7 +591,6 @@ inline namespace fundamentals_v1
    struct __is_fast_hash<hash<experimental::string_view>> : std::false_type
    { };

-#ifdef _GLIBCXX_USE_WCHAR_T
  template<>
    struct hash<experimental::wstring_view>
    : public __hash_base<size_t, wstring>
@ -607,7 +604,6 @@ inline namespace fundamentals_v1
  template<>
    struct __is_fast_hash<hash<experimental::wstring_view>> : std::false_type
    { };
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
  template<>
@ -665,11 +661,9 @@ namespace experimental
    operator""sv(const char* __str, size_t __len) noexcept
    { return basic_string_view<char>{__str, __len}; }

-#ifdef _GLIBCXX_USE_WCHAR_T
    inline constexpr basic_string_view<wchar_t>
    operator""sv(const wchar_t* __str, size_t __len) noexcept
    { return basic_string_view<wchar_t>{__str, __len}; }
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
    inline constexpr basic_string_view<char8_t>
--- a/libstdc++-v3/include/std/string
+++ b/libstdc++-v3/include/std/string
@ -68,9 +68,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #endif
    using u16string = basic_string<char16_t>;
    using u32string = basic_string<char32_t>;
-#ifdef _GLIBCXX_USE_WCHAR_T
    using wstring   = basic_string<wchar_t>;
-#endif
  } // namespace pmr

  template<typename _Str>
@ -100,12 +98,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    struct hash<pmr::u32string>
    : public __hash_string_base<pmr::u32string>
    { };
-#ifdef _GLIBCXX_USE_WCHAR_T
  template<>
    struct hash<pmr::wstring>
    : public __hash_string_base<pmr::wstring>
    { };
-#endif

 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@ -674,9 +674,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  // basic_string_view typedef names

  using string_view = basic_string_view<char>;
-#ifdef _GLIBCXX_USE_WCHAR_T
  using wstring_view = basic_string_view<wchar_t>;
-#endif
 #ifdef _GLIBCXX_USE_CHAR8_T
  using u8string_view = basic_string_view<char8_t>;
 #endif
@ -701,7 +699,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    struct __is_fast_hash<hash<string_view>> : std::false_type
    { };

-#ifdef _GLIBCXX_USE_WCHAR_T
  template<>
    struct hash<wstring_view>
    : public __hash_base<size_t, wstring_view>
@ -715,7 +712,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  template<>
    struct __is_fast_hash<hash<wstring_view>> : std::false_type
    { };
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
  template<>
@ -770,11 +766,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    operator""sv(const char* __str, size_t __len) noexcept
    { return basic_string_view<char>{__str, __len}; }

-#ifdef _GLIBCXX_USE_WCHAR_T
    inline constexpr basic_string_view<wchar_t>
    operator""sv(const wchar_t* __str, size_t __len) noexcept
    { return basic_string_view<wchar_t>{__str, __len}; }
-#endif

 #ifdef _GLIBCXX_USE_CHAR8_T
    inline constexpr basic_string_view<char8_t>