YouCompleteMe/cpp/BoostParts/boost/intrusive/detail/parent_from_member.hpp
2013-03-16 11:00:13 -07:00

94 lines
3.1 KiB
C++

/////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2007-2012
//
// 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 http://www.boost.org/libs/intrusive for documentation.
//
/////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTRUSIVE_DETAIL_PARENT_FROM_MEMBER_HPP
#define BOOST_INTRUSIVE_DETAIL_PARENT_FROM_MEMBER_HPP
#include <boost/intrusive/detail/config_begin.hpp>
#include <cstddef>
#if defined(BOOST_MSVC) || ((defined(_WIN32) || defined(__WIN32__) || defined(WIN32)) && defined(BOOST_INTEL))
#define BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER
#include <boost/cstdint.hpp>
#endif
namespace boost {
namespace intrusive {
namespace detail {
template<class Parent, class Member>
inline std::ptrdiff_t offset_from_pointer_to_member(const Member Parent::* ptr_to_member)
{
//The implementation of a pointer to member is compiler dependent.
#if defined(BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER)
//msvc compliant compilers use their the first 32 bits as offset (even in 64 bit mode)
union caster_union
{
const Member Parent::* ptr_to_member;
boost::int32_t offset;
} caster;
caster.ptr_to_member = ptr_to_member;
return std::ptrdiff_t(caster.offset);
//This works with gcc, msvc, ac++, ibmcpp
#elif defined(__GNUC__) || defined(__HP_aCC) || defined(BOOST_INTEL) || \
defined(__IBMCPP__) || defined(__DECCXX)
const Parent * const parent = 0;
const char *const member = static_cast<const char*>(static_cast<const void*>(&(parent->*ptr_to_member)));
return std::ptrdiff_t(member - static_cast<const char*>(static_cast<const void*>(parent)));
#else
//This is the traditional C-front approach: __MWERKS__, __DMC__, __SUNPRO_CC
union caster_union
{
const Member Parent::* ptr_to_member;
std::ptrdiff_t offset;
} caster;
caster.ptr_to_member = ptr_to_member;
return caster.offset - 1;
#endif
}
template<class Parent, class Member>
inline Parent *parent_from_member(Member *member, const Member Parent::* ptr_to_member)
{
return static_cast<Parent*>
(
static_cast<void*>
(
static_cast<char*>(static_cast<void*>(member)) - offset_from_pointer_to_member(ptr_to_member)
)
);
}
template<class Parent, class Member>
inline const Parent *parent_from_member(const Member *member, const Member Parent::* ptr_to_member)
{
return static_cast<const Parent*>
(
static_cast<const void*>
(
static_cast<const char*>(static_cast<const void*>(member)) - offset_from_pointer_to_member(ptr_to_member)
)
);
}
} //namespace detail {
} //namespace intrusive {
} //namespace boost {
#ifdef BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER
#undef BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER
#endif
#include <boost/intrusive/detail/config_end.hpp>
#endif //#ifndef BOOST_INTRUSIVE_DETAIL_PARENT_FROM_MEMBER_HPP