// Allocators -*- C++ -*-
// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
// 2011 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
* Copyright (c) 1996-1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file bits/allocator.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{memory}
*/
#ifndef _ALLOCATOR_H
#define _ALLOCATOR_H 1
// Define the base class to std::allocator.
#include <bits/c++allocator.h>
#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <type_traits> // For _GLIBCXX_HAS_NESTED_TYPE
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @defgroup allocators Allocators
* @ingroup memory
*
* Classes encapsulating memory operations.
*/
template<typename _Tp>
class allocator;
/// allocator<void> specialization.
template<>
class allocator<void>
{
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;
typedef const void* const_pointer;
typedef void value_type;
template<typename _Tp1>
struct rebind
{ typedef allocator<_Tp1> other; };
};
/**
* @brief The @a standard allocator, as per [20.4].
* @ingroup allocators
*
* Further details:
* http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html
*/
template<typename _Tp>
class allocator: public __glibcxx_base_allocator<_Tp>
{
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Tp* pointer;
typedef const _Tp* const_pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
typedef _Tp value_type;
template<typename _Tp1>
struct rebind
{ typedef allocator<_Tp1> other; };
allocator() throw() { }
allocator(const allocator& __a) throw()
: __glibcxx_base_allocator<_Tp>(__a) { }
template<typename _Tp1>
allocator(const allocator<_Tp1>&) throw() { }
~allocator() throw() { }
// Inherit everything else.
};
template<typename _T1, typename _T2>
inline bool
operator==(const allocator<_T1>&, const allocator<_T2>&)
{ return true; }
template<typename _Tp>
inline bool
operator==(const allocator<_Tp>&, const allocator<_Tp>&)
{ return true; }
template<typename _T1, typename _T2>
inline bool
operator!=(const allocator<_T1>&, const allocator<_T2>&)
{ return false; }
template<typename _Tp>
inline bool
operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
{ return false; }
// Inhibit implicit instantiations for required instantiations,
// which are defined via explicit instantiations elsewhere.
#if _GLIBCXX_EXTERN_TEMPLATE
extern template class allocator<char>;
extern template class allocator<wchar_t>;
#endif
// Undefine.
#undef __glibcxx_base_allocator
// To implement Option 3 of DR 431.
template<typename _Alloc, bool = __is_empty(_Alloc)>
struct __alloc_swap
{ static void _S_do_it(_Alloc&, _Alloc&) { } };
template<typename _Alloc>
struct __alloc_swap<_Alloc, false>
{
static void
_S_do_it(_Alloc& __one, _Alloc& __two)
{
// Precondition: swappable allocators.
if (__one != __two)
swap(__one, __two);
}
};
// Optimize for stateless allocators.
template<typename _Alloc, bool = __is_empty(_Alloc)>
struct __alloc_neq
{
static bool
_S_do_it(const _Alloc&, const _Alloc&)
{ return false; }
};
template<typename _Alloc>
struct __alloc_neq<_Alloc, false>
{
static bool
_S_do_it(const _Alloc& __one, const _Alloc& __two)
{ return __one != __two; }
};
#ifdef __GXX_EXPERIMENTAL_CXX0X__
// A very basic implementation for now. In general we have to wait for
// the availability of the infrastructure described in N2983: we should
// try when either T has a move constructor which cannot throw or T is
// CopyContructible.
// NB: This code doesn't properly belong here, we should find a more
// suited place common to std::vector and std::deque.
template<typename _Tp,
bool = __has_trivial_copy(typename _Tp::value_type)>
struct __shrink_to_fit
{ static void _S_do_it(_Tp&) { } };
template<typename _Tp>
struct __shrink_to_fit<_Tp, true>
{
static void
_S_do_it(_Tp& __v)
{
__try
{ _Tp(__v).swap(__v); }
__catch(...) { }
}
};
/// [allocator.tag]
struct allocator_arg_t { };
constexpr allocator_arg_t allocator_arg = allocator_arg_t();
_GLIBCXX_HAS_NESTED_TYPE(allocator_type)
template<typename _Tp, typename _Alloc,
bool = __has_allocator_type<_Tp>::value>
struct __uses_allocator_helper
: public false_type { };
template<typename _Tp, typename _Alloc>
struct __uses_allocator_helper<_Tp, _Alloc, true>
: public integral_constant<bool, is_convertible<_Alloc,
typename _Tp::allocator_type>::value>
{ };
/// [allocator.uses.trait]
template<typename _Tp, typename _Alloc>
struct uses_allocator
: public integral_constant<bool,
__uses_allocator_helper<_Tp, _Alloc>::value>
{ };
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif