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( BOOST_BORLANDC ) && ( BOOST_BORLANDC < 0x630 )
30# define BOOST_SP_NO_SP_CONVERTIBLE
31#endif
32
33#if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
34
35namespace boost
36{
37
38namespace detail
39{
40
41template< 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
52template< class Y, class T > struct sp_convertible< Y, T[] >
53{
54 enum _vt { value = false };
55};
56
57template< class Y, class T > struct sp_convertible< Y[], T[] >
58{
59 enum _vt { value = sp_convertible< Y[1], T[1] >::value };
60};
61
62template< 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
67struct sp_empty
68{
69};
70
71template< bool > struct sp_enable_if_convertible_impl;
72
73template<> struct sp_enable_if_convertible_impl<true>
74{
75 typedef sp_empty type;
76};
77
78template<> struct sp_enable_if_convertible_impl<false>
79{
80};
81
82template< 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
93

source code of include/boost/smart_ptr/detail/sp_convertible.hpp