[gcc r12-4264] libstdc++: Enable vstring for wchar_t unconditionally [PR98725]

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:4997c8b30ecfc82f9e6ce874cbd3840e227522eb

commit r12-4264-g4997c8b30ecfc82f9e6ce874cbd3840e227522eb
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Oct 8 14:48:04 2021 +0100

    libstdc++: Enable vstring for wchar_t unconditionally [PR98725]
    
    None of these vstring specializations depend on libc support for
    wchar_t, so can be enabled unconditionally now that char_traits<wchar_t>
    is always available.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/98725
            * include/ext/rc_string_base.h [!_GLIBCXX_USE_WCHAR_T]
            (__rc_string_base<wchar_t>): Define member function.
            * include/ext/vstring.h [!_GLIBCXX_USE_WCHAR_T]
            (hash<__gnu_cxx::__wvstring>): Define specialization.
            * include/ext/vstring_fwd.h [!_GLIBCXX_USE_WCHAR_T] (__wvstring)
            (__wsso_string, __wrc_string): Declare typedefs.

Diff:
---
 libstdc++-v3/include/ext/rc_string_base.h | 2 --
 libstdc++-v3/include/ext/vstring.h        | 2 --
 libstdc++-v3/include/ext/vstring_fwd.h    | 2 --
 3 files changed, 6 deletions(-)

diff --git a/libstdc++-v3/include/ext/rc_string_base.h b/libstdc++-v3/include/ext/rc_string_base.h
index 819f52dc914..88cc656448a 100644
--- a/libstdc++-v3/include/ext/rc_string_base.h
+++ b/libstdc++-v3/include/ext/rc_string_base.h
@@ -719,7 +719,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return false;
     }
 
-#ifdef _GLIBCXX_USE_WCHAR_T
   template<>
     inline bool
     __rc_string_base<wchar_t, std::char_traits<wchar_t>,
@@ -730,7 +729,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	return true;
       return false;
     }
-#endif
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
diff --git a/libstdc++-v3/include/ext/vstring.h b/libstdc++-v3/include/ext/vstring.h
index db02af18cb1..cb5872a7030 100644
--- a/libstdc++-v3/include/ext/vstring.h
+++ b/libstdc++-v3/include/ext/vstring.h
@@ -2921,7 +2921,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       { return std::_Hash_impl::hash(__s.data(), __s.length()); }
     };
 
-#ifdef _GLIBCXX_USE_WCHAR_T
   /// std::hash specialization for __wvstring.
   template<>
     struct hash<__gnu_cxx::__wvstring>
@@ -2932,7 +2931,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       { return std::_Hash_impl::hash(__s.data(),
                                      __s.length() * sizeof(wchar_t)); }
     };
-#endif
 
   /// std::hash specialization for __u16vstring.
   template<>
diff --git a/libstdc++-v3/include/ext/vstring_fwd.h b/libstdc++-v3/include/ext/vstring_fwd.h
index 645c328104f..1aa53fdc24a 100644
--- a/libstdc++-v3/include/ext/vstring_fwd.h
+++ b/libstdc++-v3/include/ext/vstring_fwd.h
@@ -58,13 +58,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   __versa_string<char, std::char_traits<char>,
 		 std::allocator<char>, __rc_string_base>    __rc_string;
 
-#ifdef _GLIBCXX_USE_WCHAR_T
   typedef __versa_string<wchar_t>                           __wvstring;
   typedef __wvstring                                        __wsso_string;
   typedef
   __versa_string<wchar_t, std::char_traits<wchar_t>,
 		 std::allocator<wchar_t>, __rc_string_base> __wrc_string;
-#endif  
 
 #if __cplusplus >= 201103L
   typedef __versa_string<char16_t>                          __u16vstring;