This fixes a new ambiguity in C++17 mode introduced by string_view
support in basic_string.
PR libstdc++/79162
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI]
(basic_string<C,T,A>::operator=(basic_string_view<C,T>)): Replace
with a constrained template.
[!_GLIBCXX_USE_CXX11_ABI]
(basic_string<C,T,A>::operator=(basic_string_view<C,T>)): Likewise.
* testsuite/21_strings/basic_string/cons/char/79162.cc: New test.
* testsuite/21_strings/basic_string/cons/wchar_t/79162.cc: New test.
Tested ppc64le-linux, committed to trunk.
commit 14b75fa34a68bfbc60fc20685bcb19e152b4cc56
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Mar 14 13:47:12 2017 +0000
PR libstdc++/79162 disambiguate assignment from string_view
PR libstdc++/79162
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI]
(basic_string<C,T,A>::operator=(basic_string_view<C,T>)): Replace
with a constrained template.
[!_GLIBCXX_USE_CXX11_ABI]
(basic_string<C,T,A>::operator=(basic_string_view<C,T>)): Likewise.
* testsuite/21_strings/basic_string/cons/char/79162.cc: New test.
* testsuite/21_strings/basic_string/cons/wchar_t/79162.cc: New test.
diff --git a/libstdc++-v3/include/bits/basic_string.h
b/libstdc++-v3/include/bits/basic_string.h
index 981ffc5..b6693c4 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -758,9 +758,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
* @brief Set value to string constructed from a string_view.
* @param __sv A string_view.
*/
- basic_string&
- operator=(__sv_type __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(_Tp __sv)
+ { return this->assign(__sv); }
/**
* @brief Convert to a string_view.
@@ -3560,9 +3561,10 @@ _GLIBCXX_END_NAMESPACE_CXX11
* @brief Set value to string constructed from a string_view.
* @param __sv A string_view.
*/
- basic_string&
- operator=(__sv_type __sv)
- { return this->assign(__sv); }
+ template<typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ operator=(_Tp __sv)
+ { return this->assign(__sv); }
/**
* @brief Convert to a string_view.
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/79162.cc
b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/79162.cc
new file mode 100644
index 0000000..0afbe11
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/79162.cc
@@ -0,0 +1,28 @@
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++1z } }
+
+#include <string>
+
+void
+test01()
+{
+ std::string s;
+ s = {"abc", 1};
+}
diff --git
a/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/79162.cc
b/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/79162.cc
new file mode 100644
index 0000000..0afbe11
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/wchar_t/79162.cc
@@ -0,0 +1,28 @@
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++1z } }
+
+#include <string>
+
+void
+test01()
+{
+ std::string s;
+ s = {"abc", 1};
+}
