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xahaud/beast/intrusive/PointerTraits.h
2013-09-05 04:22:25 -07:00

88 lines
2.6 KiB
C++

//------------------------------------------------------------------------------
/*
This file is part of Beast: https://github.com/vinniefalco/Beast
Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef BEAST_INTRUSIVE_POINTERTRAITS_H_INCLUDED
#define BEAST_INTRUSIVE_POINTERTRAITS_H_INCLUDED
namespace beast {
namespace intrusive {
// an unspecialized PointerTraits is ill-defined
template <typename P>
struct PointerTraits;
// specializations to remove cv-qualifiers
template <typename P>
struct PointerTraits <P const> : PointerTraits <P> { };
template <typename P>
struct PointerTraits <P volatile> : PointerTraits <P> { };
template <typename P>
struct PointerTraits <P const volatile> : PointerTraits <P> { };
// specialization to remove a reference attribute
template <typename P>
struct PointerTraits <P&> : PointerTraits <P> { };
// specialization for raw pointers
template <typename T>
struct PointerTraits <T*>
{
typedef T element_type;
typedef T* pointer;
typedef T& reference;
typedef std::ptrdiff_t difference_type;
template <class U>
struct rebind_pointer
{
typedef U* type;
};
static pointer pointer_to (reference r)
{
return static_cast <pointer> (
static_cast <void*> (
const_cast <char*> (
&reinterpret_cast <const char&> (
r))));
}
template <class U>
static pointer static_cast_from (U* u)
{
return static_cast <pointer> (u);
}
template <class U>
static pointer const_cast_from (U* u)
{
return const_cast <pointer> (u);
}
template <class U>
static pointer dynamic_cast_from (U* u)
{
return dynamic_cast <pointer> (u);
}
};
}
}
#endif