Prevent recursive instantiation in std::function

PR libstdc++/69005
	PR libstdc++/69222
	* include/std/functional (function::_Invoke): Remove, use result_of.
	(function::_Callable): Replace alias template with class template
	and use partial specialization instead of _NotSelf alias template.
	(function(_Functor)): Add "not self" constraint so that _Callable is
	not used while type is incomplete.
	* testsuite/20_util/function/69222.cc: New.

From-SVN: r232273
This commit is contained in:
Jonathan Wakely 2016-01-12 14:54:33 +00:00 committed by Jonathan Wakely
parent 3c4e91c903
commit 1c3c7c4145
3 changed files with 47 additions and 11 deletions

View File

@ -1,3 +1,14 @@
2016-01-12 Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/69005
PR libstdc++/69222
* include/std/functional (function::_Invoke): Remove, use result_of.
(function::_Callable): Replace alias template with class template
and use partial specialization instead of _NotSelf alias template.
(function(_Functor)): Add "not self" constraint so that _Callable is
not used while type is incomplete.
* testsuite/20_util/function/69222.cc: New.
2016-01-11 Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/60976

View File

@ -1846,20 +1846,14 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
{
typedef _Res _Signature_type(_ArgTypes...);
template<typename _Functor>
using _Invoke
= decltype(std::__callable_functor(std::declval<_Functor&>())
(std::declval<_ArgTypes>()...) );
template<typename _Func,
typename _Res2 = typename result_of<_Func(_ArgTypes...)>::type>
struct _Callable : __check_func_return_type<_Res2, _Res> { };
// Used so the return type convertibility checks aren't done when
// performing overload resolution for copy construction/assignment.
template<typename _Tp>
using _NotSelf = __not_<is_same<_Tp, function>>;
template<typename _Functor>
using _Callable
= __and_<_NotSelf<_Functor>,
__check_func_return_type<_Invoke<_Functor>, _Res>>;
struct _Callable<function, _Tp> : false_type { };
template<typename _Cond, typename _Tp>
using _Requires = typename enable_if<_Cond::value, _Tp>::type;
@ -1924,6 +1918,7 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
* reference_wrapper<F>, this function will not throw.
*/
template<typename _Functor,
typename = _Requires<__not_<is_same<_Functor, function>>, void>,
typename = _Requires<_Callable<_Functor>, void>>
function(_Functor);
@ -2116,7 +2111,7 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
}
template<typename _Res, typename... _ArgTypes>
template<typename _Functor, typename>
template<typename _Functor, typename, typename>
function<_Res(_ArgTypes...)>::
function(_Functor __f)
: _Function_base()

View File

@ -0,0 +1,30 @@
// Copyright (C) 2016 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++11" }
// { dg-do compile }
#include <functional>
// Reduced from c++/69005
struct Foo {
std::function<void(Foo)> f;
};
extern Foo exfoo;
Foo f(exfoo);
Foo& r = f = exfoo;