1
2#ifndef BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED
3#define BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED
4
5// Copyright Aleksey Gurtovoy 2000-2004
6//
7// Distributed under the Boost Software License, Version 1.0.
8// (See accompanying file LICENSE_1_0.txt or copy at
9// http://www.boost.org/LICENSE_1_0.txt)
10//
11// See http://www.boost.org/libs/mpl for documentation.
12
13// $Id$
14// $Date$
15// $Revision$
16
17#include <boost/mpl/O1_size_fwd.hpp>
18#include <boost/mpl/long.hpp>
19#include <boost/mpl/if.hpp>
20#include <boost/mpl/aux_/has_size.hpp>
21#include <boost/mpl/aux_/config/forwarding.hpp>
22#include <boost/mpl/aux_/config/static_constant.hpp>
23#include <boost/mpl/aux_/config/msvc.hpp>
24#include <boost/mpl/aux_/config/workaround.hpp>
25
26namespace boost { namespace mpl {
27
28// default implementation - returns 'Sequence::size' if sequence has a 'size'
29// member, and -1 otherwise; conrete sequences might override it by
30// specializing either the 'O1_size_impl' or the primary 'O1_size' template
31
32# if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) \
33 && !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
34
35namespace aux {
36template< typename Sequence > struct O1_size_impl
37 : Sequence::size
38{
39};
40}
41
42template< typename Tag >
43struct O1_size_impl
44{
45 template< typename Sequence > struct apply
46#if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)
47 : if_<
48 aux::has_size<Sequence>
49 , aux::O1_size_impl<Sequence>
50 , long_<-1>
51 >::type
52 {
53#else
54 {
55 typedef typename if_<
56 aux::has_size<Sequence>
57 , aux::O1_size_impl<Sequence>
58 , long_<-1>
59 >::type type;
60
61 BOOST_STATIC_CONSTANT(long, value =
62 (if_<
63 aux::has_size<Sequence>
64 , aux::O1_size_impl<Sequence>
65 , long_<-1>
66 >::type::value)
67 );
68#endif
69 };
70};
71
72# else // BOOST_MSVC
73
74template< typename Tag >
75struct O1_size_impl
76{
77 template< typename Sequence > struct apply
78 : long_<-1>
79 {
80 };
81};
82
83# endif
84
85}}
86
87#endif // BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED
88

source code of include/boost/mpl/aux_/O1_size_impl.hpp