This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[patch] libstdc++/61947 fix constructor ambiguity in std::tuple
- From: Jonathan Wakely <jwakely at redhat dot com>
- To: libstdc++ at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Tue, 29 Jul 2014 18:33:57 +0100
- Subject: [patch] libstdc++/61947 fix constructor ambiguity in std::tuple
- Authentication-results: sourceware.org; auth=none
This adds a tag parameter to the tuple base class constructors that
are used to implement uses-allocator construction but currently only
have a single parameter, ensuring they are not viable candidates when
calling a single-argument constructor.
Tested x86_64-linux, committed to trunk. I plan to fix this on the
release branches too at some point.
commit 007f346ea8b17e323fedba0c425f80ee3f8fddee
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Jul 29 16:35:10 2014 +0100
PR libstdc++/61947
* include/std/tuple (_Head_base): Use allocator_arg_t parameters to
disambiguate unary constructors.
(_Tuple_impl): Pass allocator_arg_t arguments.
* testsuite/20_util/tuple/61947.cc: New.
* testsuite/20_util/uses_allocator/cons_neg.cc: Adjust dg-error line.
diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index ef8aa5a..6c1032f 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -61,21 +61,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr _Head_base(const _Head& __h)
: _Head(__h) { }
- template<typename _UHead, typename = typename
- enable_if<!is_convertible<_UHead,
- __uses_alloc_base>::value>::type>
+ constexpr _Head_base(const _Head_base&) = default;
+ constexpr _Head_base(_Head_base&&) = default;
+
+ template<typename _UHead>
constexpr _Head_base(_UHead&& __h)
: _Head(std::forward<_UHead>(__h)) { }
- _Head_base(__uses_alloc0)
+ _Head_base(allocator_arg_t, __uses_alloc0)
: _Head() { }
template<typename _Alloc>
- _Head_base(__uses_alloc1<_Alloc> __a)
+ _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
: _Head(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
- _Head_base(__uses_alloc2<_Alloc> __a)
+ _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
: _Head(*__a._M_a) { }
template<typename _UHead>
@@ -106,21 +107,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr _Head_base(const _Head& __h)
: _M_head_impl(__h) { }
- template<typename _UHead, typename = typename
- enable_if<!is_convertible<_UHead,
- __uses_alloc_base>::value>::type>
+ constexpr _Head_base(const _Head_base&) = default;
+ constexpr _Head_base(_Head_base&&) = default;
+
+ template<typename _UHead>
constexpr _Head_base(_UHead&& __h)
: _M_head_impl(std::forward<_UHead>(__h)) { }
- _Head_base(__uses_alloc0)
+ _Head_base(allocator_arg_t, __uses_alloc0)
: _M_head_impl() { }
template<typename _Alloc>
- _Head_base(__uses_alloc1<_Alloc> __a)
+ _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
: _M_head_impl(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
- _Head_base(__uses_alloc2<_Alloc> __a)
+ _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
: _M_head_impl(*__a._M_a) { }
template<typename _UHead>
@@ -258,7 +260,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Alloc>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
: _Inherited(__tag, __a),
- _Base(__use_alloc<_Head>(__a)) { }
+ _Base(__tag, __use_alloc<_Head>(__a)) { }
template<typename _Alloc>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
diff --git a/libstdc++-v3/testsuite/20_util/tuple/61947.cc b/libstdc++-v3/testsuite/20_util/tuple/61947.cc
new file mode 100644
index 0000000..7e77de6
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/tuple/61947.cc
@@ -0,0 +1,29 @@
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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/>.
+
+#include <tuple>
+
+struct ConvertibleToAny {
+ template <class T> operator T() const { return T(); }
+};
+
+int main() {
+ std::tuple<ConvertibleToAny&&> t(ConvertibleToAny{});
+}
diff --git a/libstdc++-v3/testsuite/20_util/uses_allocator/cons_neg.cc b/libstdc++-v3/testsuite/20_util/uses_allocator/cons_neg.cc
index cf5d6a57..6396e26 100644
--- a/libstdc++-v3/testsuite/20_util/uses_allocator/cons_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/uses_allocator/cons_neg.cc
@@ -44,4 +44,4 @@ void test01()
tuple<Type> t(allocator_arg, a, 1);
}
-// { dg-error "no matching function" "" { target *-*-* } 91 }
+// { dg-error "no matching function" "" { target *-*-* } 92 }