/* Copyright 2003-2009 Joaquin M Lopez Munoz.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See Boost website at http://www.boost.org/
*/
#ifndef BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP
#define BOOST_DETAIL_ALLOCATOR_UTILITIES_HPP
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
#include <boost/detail/workaround.hpp>
#include <boost/mpl/aux_/msvc_never_true.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/type_traits/is_same.hpp>
#include <cstddef>
#include <memory>
#include <new>
namespace boost{
namespace detail{
/* Allocator adaption layer. Some stdlibs provide allocators without rebind
* and template ctors. These facilities are simulated with the external
* template class rebind_to and the aid of partial_std_allocator_wrapper.
*/
namespace allocator{
/* partial_std_allocator_wrapper inherits the functionality of a std
* allocator while providing a templatized ctor and other bits missing
* in some stdlib implementation or another.
*/
template<typename Type>
class partial_std_allocator_wrapper:public std::allocator<Type>
{
public:
/* Oddly enough, STLport does not define std::allocator<void>::value_type
* when configured to work without partial template specialization.
* No harm in supplying the definition here unconditionally.
*/
typedef Type value_type;
partial_std_allocator_wrapper(){};
template<typename Other>
partial_std_allocator_wrapper(const partial_std_allocator_wrapper<Other>&){}
partial_std_allocator_wrapper(const std::allocator<Type>& x):
std::allocator<Type>(x)
{
};
#if defined(BOOST_DINKUMWARE_STDLIB)
/* Dinkumware guys didn't provide a means to call allocate() without
* supplying a hint, in disagreement with the standard.
*/
Type* allocate(std::size_t n,const void* hint=0)
{
std::allocator<Type>& a=*this;
return a.allocate(n,hint);
}
#endif
};
/* Detects whether a given allocator belongs to a defective stdlib not
* having the required member templates.
* Note that it does not suffice to check the Boost.Config stdlib
* macros, as the user might have passed a custom, compliant allocator.
* The checks also considers partial_std_allocator_wrapper to be
* a standard defective allocator.
*/
#if defined(BOOST_NO_STD_ALLOCATOR)&&\
(defined(BOOST_HAS_PARTIAL_STD_ALLOCATOR)||defined(BOOST_DINKUMWARE_STDLIB))
template<typename Allocator>
struct is_partial_std_allocator
{
BOOST_STATIC_CONSTANT(bool,
value=
(is_same<
std::allocator<BOOST_DEDUCED_TYPENAME Allocator::value_type>,
Allocator
>::value)||
(is_same<
partial_std_allocator_wrapper<
BOOST_DEDUCED_TYPENAME Allocator::value_type>,
Allocator
>::value));
};
#else
template<typename Allocator>
struct is_partial_std_allocator
{
BOOST_STATIC_CONSTANT(bool,value=false);
};
#endif
/* rebind operations for defective std allocators */
template<typename Allocator,typename Type>
struct partial_std_allocator_rebind_to
{
typedef partial_std_allocator_wrapper<Type> type;
};
/* rebind operation in all other cases */
#if BOOST_WORKAROUND(BOOST_MSVC,<1300)
/* Workaround for a problem in MSVC with dependent template typedefs
* when doing rebinding of allocators.
* Modeled after <boost/mpl/aux_/msvc_dtw.hpp> (thanks, Aleksey!)
*/
template<typename Allocator>
struct rebinder
{
template<bool> struct fake_allocator:Allocator{};
template<> struct fake_allocator<true>
{
template<typename Type> struct rebind{};
};
template<typename Type>
struct result:
fake_allocator<mpl::aux::msvc_never_true<Allocator>::value>::
template rebind<Type>
{
};
};
#else
template<typename Allocator>
struct rebinder
{
template<typename Type>
struct result
{
typedef typename Allocator::BOOST_NESTED_TEMPLATE
rebind<Type>::other other;
};
};
#endif
template<typename Allocator,typename Type>
struct compliant_allocator_rebind_to
{
typedef typename rebinder<Allocator>::
BOOST_NESTED_TEMPLATE result<Type>::other type;
};
/* rebind front-end */
template<typename Allocator,typename Type>
struct rebind_to:
mpl::eval_if_c<
is_partial_std_allocator<Allocator>::value,
partial_std_allocator_rebind_to<Allocator,Type>,
compliant_allocator_rebind_to<Allocator,Type>
>
{
};
/* allocator-independent versions of construct and destroy */
template<typename Type>
void construct(void* p,const Type& t)
{
new (p) Type(t);
}
#if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500))
/* MSVC++ issues spurious warnings about unreferencend formal parameters
* in destroy<Type> when Type is a class with trivial dtor.
*/
#pragma warning(push)
#pragma warning(disable:4100)
#endif
template<typename Type>
void destroy(const Type* p)
{
#if BOOST_WORKAROUND(__SUNPRO_CC,BOOST_TESTED_AT(0x590))
const_cast<Type*>(p)->~Type();
#else
p->~Type();
#endif
}
#if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1500))
#pragma warning(pop)
#endif
} /* namespace boost::detail::allocator */
} /* namespace boost::detail */
} /* namespace boost */
#endif
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