1 | // (C) Copyright Jonathan Turkanis 2003.
|
---|
2 | // Distributed under the Boost Software License, Version 1.0. (See accompanying
|
---|
3 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
|
---|
4 |
|
---|
5 | // See http://www.boost.org/libs/iostreams for documentation.
|
---|
6 |
|
---|
7 | #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
|
---|
8 | #define BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
|
---|
9 |
|
---|
10 | #include <boost/config.hpp> // BOOST_STATIC_CONSTANT.
|
---|
11 | #include <boost/iostreams/detail/template_params.hpp>
|
---|
12 | #include <boost/mpl/aux_/lambda_support.hpp>
|
---|
13 | #include <boost/mpl/bool.hpp>
|
---|
14 | #include <boost/preprocessor/cat.hpp>
|
---|
15 | #include <boost/preprocessor/repetition/enum_params.hpp>
|
---|
16 | #include <boost/type_traits/detail/yes_no_type.hpp>
|
---|
17 |
|
---|
18 | //
|
---|
19 | // Macro name: BOOST_IOSTREAMS_BOOL_TRAIT_DEF
|
---|
20 | // Description: Used to generate the traits classes is_istream, is_ostream,
|
---|
21 | // etc.
|
---|
22 | //
|
---|
23 | #if BOOST_WORKAROUND(__BORLANDC__, <= 0x564)
|
---|
24 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait)
|
---|
25 | #else
|
---|
26 | # define BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) BOOST_PP_CAT(trait, _impl_)::
|
---|
27 | #endif
|
---|
28 | #define BOOST_IOSTREAMS_BOOL_TRAIT_DEF(trait, type, arity) \
|
---|
29 | namespace BOOST_PP_CAT(trait, _impl_) { \
|
---|
30 | BOOST_IOSTREAMS_TEMPLATE_PARAMS(arity, T) \
|
---|
31 | type_traits::yes_type helper \
|
---|
32 | (const volatile type BOOST_IOSTREAMS_TEMPLATE_ARGS(arity, T)*); \
|
---|
33 | type_traits::no_type helper(...); \
|
---|
34 | template<typename T> \
|
---|
35 | struct impl { \
|
---|
36 | BOOST_STATIC_CONSTANT(bool, value = \
|
---|
37 | (sizeof(BOOST_IOSTREAMS_TRAIT_NAMESPACE(trait) \
|
---|
38 | helper(static_cast<T*>(0))) == \
|
---|
39 | sizeof(type_traits::yes_type))); \
|
---|
40 | }; \
|
---|
41 | } \
|
---|
42 | template<typename T> \
|
---|
43 | struct trait \
|
---|
44 | : mpl::bool_<BOOST_PP_CAT(trait, _impl_)::impl<T>::value> \
|
---|
45 | { BOOST_MPL_AUX_LAMBDA_SUPPORT(1, trait, (T)) }; \
|
---|
46 | /**/
|
---|
47 |
|
---|
48 | #endif // #ifndef BOOST_IOSTREAMS_DETAIL_BOOL_TRAIT_DEF_HPP_INCLUDED
|
---|