PR libstdc++/79162 Fix std::string regression due to LWG 2946 (old ABI)

	PR libstdc++/79162
	* include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
	(basic_string::_If_sv): Remove from the overload set when the
	argument is derived from basic_string.

From-SVN: r253035

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ceb883e..9be1db7 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,6 +1,11 @@
 2017-09-20  Jonathan Wakely  <jwakely@redhat.com>
 
        PR libstdc++/79162
+       * include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
+       (basic_string::_If_sv): Remove from the overload set when the
+       argument is derived from basic_string.
+
+       PR libstdc++/79162
        * include/bits/basic_string.h (basic_string::_If_sv): Remove from the
        overload set when the argument is derived from basic_string.
        * testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc: New

diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index 8a382d5..a4b8113 100644 (file)
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -3439,6 +3439,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
       template<typename _Tp, typename _Res>
        using _If_sv = enable_if_t<
          __and_<is_convertible<const _Tp&, __sv_type>,
+                __not_<is_convertible<const _Tp*, const basic_string*>>,
                 __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
          _Res>;