ext-boost/boost/intrusive/detail/pointer_element.hpp
2014-12-28 01:22:08 -02:00

171 lines
5.1 KiB
C++

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2014-2014. 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_POINTER_ELEMENT_HPP
#define BOOST_INTRUSIVE_DETAIL_POINTER_ELEMENT_HPP
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/intrusive/detail/workaround.hpp>
namespace boost {
namespace intrusive {
namespace detail{
//////////////////////
//struct first_param
//////////////////////
template <typename T> struct first_param
{ typedef void type; };
#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
template <template <typename, typename...> class TemplateClass, typename T, typename... Args>
struct first_param< TemplateClass<T, Args...> >
{
typedef T type;
};
#else //C++03 compilers
template < template //0arg
<class
> class TemplateClass, class T
>
struct first_param
< TemplateClass<T> >
{ typedef T type; };
template < template //1arg
<class,class
> class TemplateClass, class T
, class P0>
struct first_param
< TemplateClass<T, P0> >
{ typedef T type; };
template < template //2arg
<class,class,class
> class TemplateClass, class T
, class P0, class P1>
struct first_param
< TemplateClass<T, P0, P1> >
{ typedef T type; };
template < template //3arg
<class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2>
struct first_param
< TemplateClass<T, P0, P1, P2> >
{ typedef T type; };
template < template //4arg
<class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3>
struct first_param
< TemplateClass<T, P0, P1, P2, P3> >
{ typedef T type; };
template < template //5arg
<class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4> >
{ typedef T type; };
template < template //6arg
<class,class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4, class P5>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4, P5> >
{ typedef T type; };
template < template //7arg
<class,class,class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4, class P5, class P6>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4, P5, P6> >
{ typedef T type; };
template < template //8arg
<class,class,class,class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4, class P5, class P6, class P7>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4, P5, P6, P7> >
{ typedef T type; };
template < template //9arg
<class,class,class,class,class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4, class P5, class P6, class P7, class P8>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4, P5, P6, P7, P8> >
{ typedef T type; };
template < template //10arg
<class,class,class,class,class,class,class,class,class,class,class
> class TemplateClass, class T
, class P0, class P1, class P2, class P3, class P4, class P5, class P6, class P7, class P8, class P9>
struct first_param
< TemplateClass<T, P0, P1, P2, P3, P4, P5, P6, P7, P8, P9> >
{ typedef T type; };
#endif //!defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
template <typename T>
struct has_internal_pointer_element
{
template <typename X>
static char test(int, typename X::element_type*);
template <typename X>
static int test(...);
static const bool value = (1 == sizeof(test<T>(0, 0)));
};
template<class Ptr, bool = has_internal_pointer_element<Ptr>::value>
struct pointer_element_impl
{
typedef typename Ptr::element_type type;
};
template<class Ptr>
struct pointer_element_impl<Ptr, false>
{
typedef typename boost::intrusive::detail::first_param<Ptr>::type type;
};
} //namespace detail{
template <typename Ptr>
struct pointer_element
{
typedef typename ::boost::intrusive::detail::pointer_element_impl<Ptr>::type type;
};
template <typename T>
struct pointer_element<T*>
{ typedef T type; };
} //namespace container {
} //namespace boost {
#endif // defined(BOOST_INTRUSIVE_DETAIL_POINTER_ELEMENT_HPP)