From: François Dumont <fdumont@gcc.gnu.org>
Date: Mon, 9 Aug 2021 09:55:43 +0000 (+0200)
Subject: libstdc++: [_GLIBCXX_DEBUG] Avoid allocator operator== when always equal
X-Git-Tag: basepoints/gcc-13~5489
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1354603bf7d2ef8cd0cb1f76e801732020502987;p=thirdparty%2Fgcc.git

libstdc++: [_GLIBCXX_DEBUG] Avoid allocator operator== when always equal

Use std::allocator_traits::is_always_equal to find out if we need to compare
allocator instances on safe container allocator aware move constructor.

libstdc++-v3/ChangeLog:

	* include/debug/safe_container.h
	(_Safe_container(_Safe_container&&, const _Alloc&, std::true_type)): New.
	(_Safe_container(_Safe_container&&, const _Alloc&, std::false_type)): New.
	(_Safe_container(_Safe_container&&, const _Alloc&)): Use latters.
---

diff --git a/libstdc++-v3/include/debug/safe_container.h b/libstdc++-v3/include/debug/safe_container.h
index d9636c29e9b5..97c47167fe8f 100644
--- a/libstdc++-v3/include/debug/safe_container.h
+++ b/libstdc++-v3/include/debug/safe_container.h
@@ -57,7 +57,12 @@ namespace __gnu_debug
       _Safe_container(const _Safe_container&) = default;
       _Safe_container(_Safe_container&&) = default;
 
-      _Safe_container(_Safe_container&& __x, const _Alloc& __a)
+    private:
+      _Safe_container(_Safe_container&& __x, const _Alloc&, std::true_type)
+      : _Safe_container(std::move(__x))
+      { }
+
+      _Safe_container(_Safe_container&& __x, const _Alloc& __a, std::false_type)
       : _Safe_container()
       {
 	if (__x._M_cont().get_allocator() == __a)
@@ -65,6 +70,12 @@ namespace __gnu_debug
 	else
 	  __x._M_invalidate_all();
       }
+
+    protected:
+      _Safe_container(_Safe_container&& __x, const _Alloc& __a)
+      : _Safe_container(std::move(__x), __a,
+		      typename std::allocator_traits<_Alloc>::is_always_equal{})
+      { }
 #endif
 
     public: