PR72792 detect allocator pointer types without invalid rebinding
PR libstdc++/72792 * include/bits/alloc_traits.h (__allocator_traits_base::__diff_type) (__allocator_traits_base::__size_type): Remove. (allocator_traits::_Ptr): New class template to detect const and void pointer types without instantiating pointer_traits::rebind unnecessarily. (allocator_traits::_Diff): Likewise for detecting difference_type. (allocator_traits::_Size): New class template to detect size_type without instantiating make_unsigned unnecessarily. * include/bits/ptr_traits.h (pointer_traits::element_type): Use __detected_or_t instead of __detected_or_t_. * include/std/type_traits (__detected_or_t_): Remove. * testsuite/20_util/allocator_traits/members/pointers.cc: New test. From-SVN: r244706
This commit is contained in:
Jonathan Wakely
Jonathan Wakely
parent
2ebd93e1d7
commit
4dfdda108f
|
|
@ -1,5 +1,19 @@
|
|||
2017-01-20 Jonathan Wakely <jwakely@redhat.com>
|
||||
|
||||
PR libstdc++/72792
|
||||
* include/bits/alloc_traits.h (__allocator_traits_base::__diff_type)
|
||||
(__allocator_traits_base::__size_type): Remove.
|
||||
(allocator_traits::_Ptr): New class template to detect const and void
|
||||
pointer types without instantiating pointer_traits::rebind
|
||||
unnecessarily.
|
||||
(allocator_traits::_Diff): Likewise for detecting difference_type.
|
||||
(allocator_traits::_Size): New class template to detect size_type
|
||||
without instantiating make_unsigned unnecessarily.
|
||||
* include/bits/ptr_traits.h (pointer_traits::element_type): Use
|
||||
__detected_or_t instead of __detected_or_t_.
|
||||
* include/std/type_traits (__detected_or_t_): Remove.
|
||||
* testsuite/20_util/allocator_traits/members/pointers.cc: New test.
|
||||
|
||||
PR libstdc++/72792
|
||||
PR libstdc++/72793
|
||||
* include/bits/alloc_traits.h (__allocator_traits_base::__rebind):
|
||||
|
|
|
|||
|
|
@ -61,10 +61,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
using __v_pointer = typename _Tp::void_pointer;
|
||||
template<typename _Tp>
|
||||
using __cv_pointer = typename _Tp::const_void_pointer;
|
||||
template<typename _Tp>
|
||||
using __diff_type = typename _Tp::difference_type;
|
||||
template<typename _Tp>
|
||||
using __size_type = typename _Tp::size_type;
|
||||
template<typename _Tp>
|
||||
using __pocca = typename _Tp::propagate_on_container_copy_assignment;
|
||||
template<typename _Tp>
|
||||
|
|
@ -98,15 +94,45 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
*/
|
||||
using pointer = __detected_or_t<value_type*, __pointer, _Alloc>;
|
||||
|
||||
private:
|
||||
// Select _Func<_Alloc> or pointer_traits<pointer>::rebind<_Tp>
|
||||
template<template<typename> class _Func, typename _Tp, typename = void>
|
||||
struct _Ptr
|
||||
{
|
||||
using type = typename pointer_traits<pointer>::template rebind<_Tp>;
|
||||
};
|
||||
|
||||
template<template<typename> class _Func, typename _Tp>
|
||||
struct _Ptr<_Func, _Tp, __void_t<_Func<_Alloc>>>
|
||||
{
|
||||
using type = _Func<_Alloc>;
|
||||
};
|
||||
|
||||
// Select _A2::difference_type or pointer_traits<_Ptr>::difference_type
|
||||
template<typename _A2, typename _PtrT, typename = void>
|
||||
struct _Diff
|
||||
{ using type = typename pointer_traits<_PtrT>::difference_type; };
|
||||
|
||||
template<typename _A2, typename _PtrT>
|
||||
struct _Diff<_A2, _PtrT, __void_t<typename _A2::difference_type>>
|
||||
{ using type = typename _A2::difference_type; };
|
||||
|
||||
// Select _A2::size_type or make_unsigned<_DiffT>::type
|
||||
template<typename _A2, typename _DiffT, typename = void>
|
||||
struct _Size : make_unsigned<_DiffT> { };
|
||||
|
||||
template<typename _A2, typename _DiffT>
|
||||
struct _Size<_A2, _DiffT, __void_t<typename _A2::size_type>>
|
||||
{ using type = typename _A2::size_type; };
|
||||
|
||||
public:
|
||||
/**
|
||||
* @brief The allocator's const pointer type.
|
||||
*
|
||||
* @c Alloc::const_pointer if that type exists, otherwise
|
||||
* <tt> pointer_traits<pointer>::rebind<const value_type> </tt>
|
||||
*/
|
||||
using const_pointer
|
||||
= __detected_or_t<__ptr_rebind<pointer, const value_type>,
|
||||
__c_pointer, _Alloc>;
|
||||
using const_pointer = typename _Ptr<__c_pointer, const value_type>::type;
|
||||
|
||||
/**
|
||||
* @brief The allocator's void pointer type.
|
||||
|
|
@ -114,8 +140,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
* @c Alloc::void_pointer if that type exists, otherwise
|
||||
* <tt> pointer_traits<pointer>::rebind<void> </tt>
|
||||
*/
|
||||
using void_pointer
|
||||
= __detected_or_t<__ptr_rebind<pointer, void>, __v_pointer, _Alloc>;
|
||||
using void_pointer = typename _Ptr<__v_pointer, void>::type;
|
||||
|
||||
/**
|
||||
* @brief The allocator's const void pointer type.
|
||||
|
|
@ -123,9 +148,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
* @c Alloc::const_void_pointer if that type exists, otherwise
|
||||
* <tt> pointer_traits<pointer>::rebind<const void> </tt>
|
||||
*/
|
||||
using const_void_pointer
|
||||
= __detected_or_t<__ptr_rebind<pointer, const void>, __cv_pointer,
|
||||
_Alloc>;
|
||||
using const_void_pointer = typename _Ptr<__cv_pointer, const void>::type;
|
||||
|
||||
/**
|
||||
* @brief The allocator's difference type
|
||||
|
|
@ -133,9 +156,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
* @c Alloc::difference_type if that type exists, otherwise
|
||||
* <tt> pointer_traits<pointer>::difference_type </tt>
|
||||
*/
|
||||
using difference_type
|
||||
= __detected_or_t<typename pointer_traits<pointer>::difference_type,
|
||||
__diff_type, _Alloc>;
|
||||
using difference_type = typename _Diff<_Alloc, pointer>::type;
|
||||
|
||||
/**
|
||||
* @brief The allocator's size type
|
||||
|
|
@ -143,9 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
* @c Alloc::size_type if that type exists, otherwise
|
||||
* <tt> make_unsigned<difference_type>::type </tt>
|
||||
*/
|
||||
using size_type
|
||||
= __detected_or_t<typename make_unsigned<difference_type>::type,
|
||||
__size_type, _Alloc>;
|
||||
using size_type = typename _Size<_Alloc, difference_type>::type;
|
||||
|
||||
/**
|
||||
* @brief How the allocator is propagated on copy assignment
|
||||
|
|
|
|||
|
|
@ -97,7 +97,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
|
||||
/// The type pointed to.
|
||||
using element_type
|
||||
= __detected_or_t_<__get_first_arg_t, __element_type, _Ptr>;
|
||||
= __detected_or_t<__get_first_arg_t<_Ptr>, __element_type, _Ptr>;
|
||||
|
||||
/// The type used to represent the difference between two pointers.
|
||||
using difference_type
|
||||
|
|
|
|||
|
|
@ -2565,12 +2565,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|||
using __detected_or_t
|
||||
= typename __detected_or<_Default, _Op, _Args...>::type;
|
||||
|
||||
// _Op<_Args...> if that is a valid type, otherwise _Default<_Args...>.
|
||||
template<template<typename...> class _Default,
|
||||
template<typename...> class _Op, typename... _Args>
|
||||
using __detected_or_t_ =
|
||||
__detected_or_t<_Default<_Args...>, _Op, _Args...>;
|
||||
|
||||
/// @} group metaprogramming
|
||||
|
||||
/**
|
||||
|
|
|
|||
|
|
@ -0,0 +1,52 @@
|
|||
// 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-do compile { target c++11 } }
|
||||
|
||||
#include <memory>
|
||||
|
||||
// Non-type template param means pointer_traits::rebind can't be instantiated.
|
||||
template<typename T, int = 0>
|
||||
struct Pointer
|
||||
{
|
||||
using element_type = T;
|
||||
Pointer(T* p = nullptr) : ptr(p) { }
|
||||
T* ptr;
|
||||
};
|
||||
|
||||
template<typename T>
|
||||
struct Alloc
|
||||
{
|
||||
using value_type = T;
|
||||
using pointer = Pointer<T>;
|
||||
using const_pointer = Pointer<const T>;
|
||||
using void_pointer = Pointer<void>;
|
||||
using const_void_pointer = Pointer<const void>;
|
||||
|
||||
pointer allocate(std::size_t n)
|
||||
{ return std::allocator<T>().allocate(n); }
|
||||
|
||||
void allocate(pointer p, std::size_t n)
|
||||
{ return std::allocator<T>().deallocate(p, n); }
|
||||
};
|
||||
|
||||
// The nested pointer types in Alloc should be found without attempting to
|
||||
// instantiate pointer_traits::rebind (which would fail):
|
||||
std::allocator_traits<Alloc<int>>::pointer p;
|
||||
std::allocator_traits<Alloc<int>>::const_pointer cp;
|
||||
std::allocator_traits<Alloc<int>>::void_pointer vp;
|
||||
std::allocator_traits<Alloc<int>>::const_void_pointer cvp;
|
||||
Loading…
Reference in New Issue