From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 10 Nov 2023 19:18:57 +0000 (+0000)
Subject: libstdc++: Simplify std::string_view comparisons (LWG 3950)
X-Git-Tag: basepoints/gcc-15~4790
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f7251b7886c47cbd5c9ffb217eb9849f023f76da;p=thirdparty%2Fgcc.git

libstdc++: Simplify std::string_view comparisons (LWG 3950)

LWG 3950 points out that the comparisons of std::basic_string_view can
be simplified to just a single overload of operator== and a single
overload of operator<=>. Those overloads work fine for homogeneous
comparisons of two string view objects.

libstdc++-v3/ChangeLog:

	* include/std/string_view (operator==, operator<=>): Remove
	redundant overloads (LWG 3950).
---

diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view
index 9deae25f7120..cf288ed3a366 100644
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@@ -602,13 +602,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // deduction and the other argument gets implicitly converted to the deduced
   // type (see N3766).
 
-  template<typename _CharT, typename _Traits>
-    [[nodiscard]]
-    constexpr bool
-    operator==(basic_string_view<_CharT, _Traits> __x,
-               basic_string_view<_CharT, _Traits> __y) noexcept
-    { return __x.size() == __y.size() && __x.compare(__y) == 0; }
-
   template<typename _CharT, typename _Traits>
     [[nodiscard]]
     constexpr bool
@@ -618,14 +611,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { return __x.size() == __y.size() && __x.compare(__y) == 0; }
 
 #if __cpp_lib_three_way_comparison
-  template<typename _CharT, typename _Traits>
-    [[nodiscard]]
-    constexpr auto
-    operator<=>(basic_string_view<_CharT, _Traits> __x,
-		basic_string_view<_CharT, _Traits> __y) noexcept
-    -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
-    { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
-
   template<typename _CharT, typename _Traits>
     [[nodiscard]]
     constexpr auto
@@ -635,6 +620,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
     { return __detail::__char_traits_cmp_cat<_Traits>(__x.compare(__y)); }
 #else
+  template<typename _CharT, typename _Traits>
+    [[nodiscard]]
+    constexpr bool
+    operator==(basic_string_view<_CharT, _Traits> __x,
+	       basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.size() == __y.size() && __x.compare(__y) == 0; }
+
   template<typename _CharT, typename _Traits>
     [[nodiscard]]
     constexpr bool