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any (any::_Storage): Make non-copyable.

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* include/experimental/any (any::_Storage): Make non-copyable.
	(any::any): Do not copy _Storage object.
	(any::operator=): Implement more efficiently than swapping.
	(any::swap): Use new _Op_xfer operation.
	(any::_Op::_Op_xfer): New enumerator.
	(_Manager_internal::_S_alloc): Remove unused function.
	(_Manager_internal::_S_create, _Manager_external::_S_create): Use out
	parameter instead of returning a _Storage object.
	(_Manager_internal::_S_manage, _Manager_external::_S_manage): Add
	_Op_xfer operation for moving and swapping.
	* testsuite/experimental/any/cons/nontrivial.cc: New.
	* testsuite/experimental/any/misc/any_cast_neg.cc: Adjust dg-error.

From-SVN: r222721
This commit is contained in:
Jonathan Wakely 2015-05-02 13:38:44 +01:00 committed by Jonathan Wakely
parent 5b244a78dc
commit 9407c6fa53
4 changed files with 180 additions and 34 deletions
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13
libstdc++-v3/ChangeLog
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@ -1,5 +1,18 @@
2015-05-02 Jonathan Wakely <jwakely@redhat.com>
* include/experimental/any (any::_Storage): Make non-copyable.
(any::any): Do not copy _Storage object.
(any::operator=): Implement more efficiently than swapping.
(any::swap): Use new _Op_xfer operation.
(any::_Op::_Op_xfer): New enumerator.
(_Manager_internal::_S_alloc): Remove unused function.
(_Manager_internal::_S_create, _Manager_external::_S_create): Use out
parameter instead of returning a _Storage object.
(_Manager_internal::_S_manage, _Manager_external::_S_manage): Add
_Op_xfer operation for moving and swapping.
* testsuite/experimental/any/cons/nontrivial.cc: New.
* testsuite/experimental/any/misc/any_cast_neg.cc: Adjust dg-error.
* include/experimental/fs_path.h (filesystem_error::~filesystem_error):
Declare.
* src/filesystem/path.cc (filesystem_error::~filesystem_error):

124
libstdc++-v3/include/experimental/any
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@ -90,6 +90,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Holds either pointer to a heap object or the contained object itself.
union _Storage
{
// This constructor intentionally doesn't initialize anything.
_Storage() = default;
// Prevent trivial copies of this type, buffer might hold a non-POD.
_Storage(const _Storage&) = delete;
_Storage& operator=(const _Storage&) = delete;
void* _M_ptr;
std::aligned_storage<sizeof(_M_ptr), sizeof(_M_ptr)>::type _M_buffer;
};
@ -119,33 +126,42 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
any() noexcept : _M_manager(nullptr) { }
/// Copy constructor, copies the state of @p __other
any(const any& __other) : _M_manager(__other._M_manager)
any(const any& __other)
{
if (!__other.empty())
if (__other.empty())
_M_manager = nullptr;
else
{
_Arg __arg;
__arg._M_any = this;
_M_manager(_Op_clone, &__other, &__arg);
__other._M_manager(_Op_clone, &__other, &__arg);
}
}
/**
* @brief Move constructor, transfer the state from @p __other
*
* @post @c __other.empty() (not guaranteed for other implementations)
* @post @c __other.empty() (this postcondition is a GNU extension)
*/
any(any&& __other) noexcept
: _M_manager(__other._M_manager),
_M_storage(__other._M_storage)
{ __other._M_manager = nullptr; }
{
if (__other.empty())
_M_manager = nullptr;
else
{
_Arg __arg;
__arg._M_any = this;
__other._M_manager(_Op_xfer, &__other, &__arg);
}
}
/// Construct with a copy of @p __value as the contained object.
template <typename _ValueType, typename _Tp = _Decay<_ValueType>,
typename _Mgr = _Manager<_Tp>>
any(_ValueType&& __value)
: _M_manager(&_Mgr::_S_manage),
_M_storage(_Mgr::_S_create(std::forward<_ValueType>(__value)))
: _M_manager(&_Mgr::_S_manage)
{
_Mgr::_S_create(_M_storage, std::forward<_ValueType>(__value));
static_assert(is_copy_constructible<_Tp>::value,
"The contained object must be CopyConstructible");
}
@ -155,10 +171,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// assignments
/// Copy the state of
/// Copy the state of another object.
any& operator=(const any& __rhs)
{
any(__rhs).swap(*this);
if (__rhs.empty())
clear();
else
{
if (!empty())
_M_manager(_Op_destroy, this, nullptr);
_Arg __arg;
__arg._M_any = this;
__rhs._M_manager(_Op_clone, &__rhs, &__arg);
}
return *this;
}
@ -169,7 +194,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
*/
any& operator=(any&& __rhs) noexcept
{
any(std::move(__rhs)).swap(*this);
if (__rhs.empty())
clear();
else
{
if (!empty())
_M_manager(_Op_destroy, this, nullptr);
_Arg __arg;
__arg._M_any = this;
__rhs._M_manager(_Op_xfer, &__rhs, &__arg);
}
return *this;
}
@ -177,7 +211,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _ValueType>
any& operator=(_ValueType&& __rhs)
{
any(std::forward<_ValueType>(__rhs)).swap(*this);
*this = any(std::forward<_ValueType>(__rhs));
return *this;
}
@ -195,10 +229,30 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Exchange state with another object.
void swap(any& __rhs) noexcept
{
std::swap(_M_manager, __rhs._M_manager);
std::swap(_M_storage, __rhs._M_storage);
}
{
if (empty() && __rhs.empty())
return;
if (!empty() && !__rhs.empty())
{
any __tmp;
_Arg __arg;
__arg._M_any = &__tmp;
__rhs._M_manager(_Op_xfer, &__rhs, &__arg);
__arg._M_any = &__rhs;
_M_manager(_Op_xfer, this, &__arg);
__arg._M_any = this;
__tmp._M_manager(_Op_xfer, &__tmp, &__arg);
}
else
{
any* __empty = empty() ? this : &__rhs;
any* __full = empty() ? &__rhs : this;
_Arg __arg;
__arg._M_any = __empty;
__full->_M_manager(_Op_xfer, __full, &__arg);
}
}
// observers
@ -222,7 +276,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ return __or_<is_reference<_Tp>, is_copy_constructible<_Tp>>::value; }
private:
enum _Op { _Op_access, _Op_get_type_info, _Op_clone, _Op_destroy };
enum _Op {
_Op_access, _Op_get_type_info, _Op_clone, _Op_destroy, _Op_xfer
};
union _Arg
{
@ -252,20 +308,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_S_manage(_Op __which, const any* __anyp, _Arg* __arg);
template<typename _Up>
static _Storage
_S_create(_Up&& __value)
static void
_S_create(_Storage& __storage, _Up&& __value)
{
_Storage __storage;
void* __addr = &__storage._M_buffer;
::new (__addr) _Tp(std::forward<_Up>(__value));
return __storage;
}
template<typename _Alloc, typename _Up>
static _Storage
_S_alloc(const _Alloc&, _Up&& __value)
{
return _S_create(std::forward<_Up>(__value));
}
};
@ -277,12 +324,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_S_manage(_Op __which, const any* __anyp, _Arg* __arg);
template<typename _Up>
static _Storage
_S_create(_Up&& __value)
static void
_S_create(_Storage& __storage, _Up&& __value)
{
_Storage __storage;
__storage._M_ptr = new _Tp(std::forward<_Up>(__value));
return __storage;
}
};
};
@ -393,10 +438,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
break;
case _Op_clone:
::new(&__arg->_M_any->_M_storage._M_buffer) _Tp(*__ptr);
__arg->_M_any->_M_manager = __any->_M_manager;
break;
case _Op_destroy:
__ptr->~_Tp();
break;
case _Op_xfer:
::new(&__arg->_M_any->_M_storage._M_buffer) _Tp(*__ptr);
__ptr->~_Tp();
__arg->_M_any->_M_manager = __any->_M_manager;
const_cast<any*>(__any)->_M_manager = nullptr;
break;
}
}
@ -419,10 +471,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
break;
case _Op_clone:
__arg->_M_any->_M_storage._M_ptr = new _Tp(*__ptr);
__arg->_M_any->_M_manager = __any->_M_manager;
break;
case _Op_destroy:
delete __ptr;
break;
case _Op_xfer:
__arg->_M_any->_M_storage._M_ptr = __any->_M_storage._M_ptr;
__arg->_M_any->_M_manager = __any->_M_manager;
const_cast<any*>(__any)->_M_manager = nullptr;
break;
}
}

75
libstdc++-v3/testsuite/experimental/any/cons/nontrivial.cc Normal file
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@ -0,0 +1,75 @@
// Copyright (C) 2015 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++14" }
#include <experimental/any>
#include <testsuite_hooks.h>
struct LocationAware
{
LocationAware() { }
~LocationAware() { VERIFY(self == this); }
LocationAware(const LocationAware&) { }
LocationAware& operator=(const LocationAware&) { return *this; }
LocationAware(LocationAware&&) noexcept { }
LocationAware& operator=(LocationAware&&) noexcept { return *this; }
void* const self = this;
};
static_assert(std::is_nothrow_move_constructible<LocationAware>::value, "");
static_assert(!std::is_trivially_copyable<LocationAware>::value, "");
using std::experimental::any;
void
test01()
{
LocationAware l;
any a = l;
}
void
test02()
{
LocationAware l;
any a = l;
any b = a;
{
any tmp = std::move(a);
a = std::move(b);
b = std::move(tmp);
}
}
void
test03()
{
LocationAware l;
any a = l;
any b = a;
swap(a, b);
}
int
main()
{
test01();
test02();
test03();
}

2
libstdc++-v3/testsuite/experimental/any/misc/any_cast_neg.cc
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@ -26,5 +26,5 @@ void test01()
using std::experimental::any_cast;
const any y(1);
any_cast<int&>(y); // { dg-error "qualifiers" "" { target { *-*-* } } 310 }
any_cast<int&>(y); // { dg-error "qualifiers" "" { target { *-*-* } } 355 }
}