boost_ext/boost/multi_index/detail/uintptr_type.hpp

   1 /* Copyright 2003-2007 Joaquín M López Muñoz.
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * See http://www.boost.org/libs/multi_index for library home page.
   7  */
   8
   9 #ifndef BOOST_MULTI_INDEX_DETAIL_UINTPTR_TYPE_HPP
  10 #define BOOST_MULTI_INDEX_DETAIL_UINTPTR_TYPE_HPP
  11
  12 #if defined(_MSC_VER)&&(_MSC_VER>=1200)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  17 #include <boost/mpl/bool.hpp>
  18
  19 namespace boost{
  20
  21 namespace multi_index{
  22
  23 namespace detail{
  24
  25 /* has_uintptr_type is an MPL integral constant determining whether
  26  * there exists an unsigned integral type with the same size as
  27  * void *.
  28  * uintptr_type is such a type if has_uintptr is true, or unsigned int
  29  * otherwise.
  30  * Note that uintptr_type is more restrictive than C99 uintptr_t,
  31  * where an integral type with size greater than that of void *
  32  * would be conformant.
  33  */
  34
  35 template<int N>struct uintptr_candidates;
  36 template<>struct uintptr_candidates<-1>{typedef unsigned int       type;};
  37 template<>struct uintptr_candidates<0> {typedef unsigned int       type;};
  38 template<>struct uintptr_candidates<1> {typedef unsigned short     type;};
  39 template<>struct uintptr_candidates<2> {typedef unsigned long      type;};
  40
  41 #if defined(BOOST_HAS_LONG_LONG)
  42 template<>struct uintptr_candidates<3> {typedef unsigned long long type;};
  43 #else
  44 template<>struct uintptr_candidates<3> {typedef unsigned int       type;};
  45 #endif
  46
  47 #if defined(BOOST_HAS_MS_INT64)
  48 template<>struct uintptr_candidates<4> {typedef unsigned __int64   type;};
  49 #else
  50 template<>struct uintptr_candidates<4> {typedef unsigned int       type;};
  51 #endif
  52
  53 struct uintptr_aux
  54 {
  55   BOOST_STATIC_CONSTANT(int,index=
  56     sizeof(void*)==sizeof(uintptr_candidates<0>::type)?0:
  57     sizeof(void*)==sizeof(uintptr_candidates<1>::type)?1:
  58     sizeof(void*)==sizeof(uintptr_candidates<2>::type)?2:
  59     sizeof(void*)==sizeof(uintptr_candidates<3>::type)?3:
  60     sizeof(void*)==sizeof(uintptr_candidates<4>::type)?4:-1);
  61
  62   BOOST_STATIC_CONSTANT(bool,has_uintptr_type=(index>=0));
  63
  64   typedef uintptr_candidates<index>::type type;
  65 };
  66
  67 typedef mpl::bool_<uintptr_aux::has_uintptr_type> has_uintptr_type;
  68 typedef uintptr_aux::type                         uintptr_type;
  69
  70 } /* namespace multi_index::detail */
  71
  72 } /* namespace multi_index */
  73
  74 } /* namespace boost */
  75
  76 #endif