ceph/src/boost/boost/smart_ptr/detail/sp_convertible.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED
   3
   4 // MS compatible compilers support #pragma once
   5
   6 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
   7 # pragma once
   8 #endif
   9
  10 //  detail/sp_convertible.hpp
  11 //
  12 //  Copyright 2008 Peter Dimov
  13 //
  14 //  Distributed under the Boost Software License, Version 1.0.
  15 //  See accompanying file LICENSE_1_0.txt or copy at
  16 //  http://www.boost.org/LICENSE_1_0.txt
  17
  18 #include <boost/config.hpp>
  19 #include <cstddef>
  20
  21 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( BOOST_NO_SFINAE )
  22 # define BOOST_SP_NO_SP_CONVERTIBLE
  23 #endif
  24
  25 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( __GNUC__ ) && ( __GNUC__ * 100 + __GNUC_MINOR__ < 303 )
  26 # define BOOST_SP_NO_SP_CONVERTIBLE
  27 #endif
  28
  29 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( __BORLANDC__ ) && ( __BORLANDC__ < 0x630 )
  30 # define BOOST_SP_NO_SP_CONVERTIBLE
  31 #endif
  32
  33 #if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
  34
  35 namespace boost
  36 {
  37
  38 namespace detail
  39 {
  40
  41 template< class Y, class T > struct sp_convertible
  42 {
  43     typedef char (&yes) [1];
  44     typedef char (&no)  [2];
  45
  46     static yes f( T* );
  47     static no  f( ... );
  48
  49     enum _vt { value = sizeof( (f)( static_cast<Y*>(0) ) ) == sizeof(yes) };
  50 };
  51
  52 template< class Y, class T > struct sp_convertible< Y, T[] >
  53 {
  54     enum _vt { value = false };
  55 };
  56
  57 template< class Y, class T > struct sp_convertible< Y[], T[] >
  58 {
  59     enum _vt { value = sp_convertible< Y[1], T[1] >::value };
  60 };
  61
  62 template< class Y, std::size_t N, class T > struct sp_convertible< Y[N], T[] >
  63 {
  64     enum _vt { value = sp_convertible< Y[1], T[1] >::value };
  65 };
  66
  67 struct sp_empty
  68 {
  69 };
  70
  71 template< bool > struct sp_enable_if_convertible_impl;
  72
  73 template<> struct sp_enable_if_convertible_impl<true>
  74 {
  75     typedef sp_empty type;
  76 };
  77
  78 template<> struct sp_enable_if_convertible_impl<false>
  79 {
  80 };
  81
  82 template< class Y, class T > struct sp_enable_if_convertible: public sp_enable_if_convertible_impl< sp_convertible< Y, T >::value >
  83 {
  84 };
  85
  86 } // namespace detail
  87
  88 } // namespace boost
  89
  90 #endif // !defined( BOOST_SP_NO_SP_CONVERTIBLE )
  91
  92 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED