projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | // Copyright David Abrahams 2005. Distributed under the Boost |
| 2 | // 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 | #ifndef BOOST_PARAMETER_BINDING_DWA200558_HPP | |
| 5 | # define BOOST_PARAMETER_BINDING_DWA200558_HPP | |
| 6 | ||
| 7 | # include <boost/mpl/apply.hpp> | |
| 8 | # include <boost/mpl/assert.hpp> | |
| 9 | # include <boost/mpl/and.hpp> | |
| 10 | # include <boost/parameter/aux_/result_of0.hpp> | |
| 11 | # include <boost/parameter/aux_/void.hpp> | |
| 12 | # include <boost/type_traits/is_same.hpp> | |
| 13 | ||
| 14 | namespace boost { namespace parameter { | |
| 15 | ||
| 16 | // A metafunction that, given an argument pack, returns the type of | |
| 17 | // the parameter identified by the given keyword. If no such | |
| 18 | // parameter has been specified, returns Default | |
| 19 | ||
| 20 | # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) | |
| 21 | template <class Parameters, class Keyword, class Default> | |
| 22 | struct binding0 | |
| 23 | { | |
| 24 | typedef typename mpl::apply_wrap3< | |
| 25 | typename Parameters::binding,Keyword,Default,mpl::true_ | |
| 26 | >::type type; | |
| 27 | ||
| 28 | BOOST_MPL_ASSERT_NOT(( | |
| 29 | mpl::and_< | |
| 30 | is_same<Default, void_> | |
| 31 | , is_same<type, void_> | |
| 32 | > | |
| 33 | )); | |
| 34 | }; | |
| 35 | # endif | |
| 36 | ||
| 37 | template <class Parameters, class Keyword, class Default = void_> | |
| 38 | struct binding | |
| 39 | { | |
| 40 | # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) | |
| 41 | typedef typename mpl::eval_if< | |
| 42 | mpl::is_placeholder<Parameters> | |
| 43 | , mpl::identity<int> | |
| 44 | , binding0<Parameters,Keyword,Default> | |
| 45 | >::type type; | |
| 46 | # else | |
| 47 | typedef typename mpl::apply_wrap3< | |
| 48 | typename Parameters::binding,Keyword,Default,mpl::true_ | |
| 49 | >::type type; | |
| 50 | ||
| 51 | BOOST_MPL_ASSERT_NOT(( | |
| 52 | mpl::and_< | |
| 53 | is_same<Default, void_> | |
| 54 | , is_same<type, void_> | |
| 55 | > | |
| 56 | )); | |
| 57 | # endif | |
| 58 | ||
| 59 | BOOST_MPL_AUX_LAMBDA_SUPPORT(3,binding,(Parameters,Keyword,Default)) | |
| 60 | }; | |
| 61 | ||
| 62 | // A metafunction that, given an argument pack, returns the type of | |
| 63 | // the parameter identified by the given keyword. If no such | |
| 64 | // parameter has been specified, returns the type returned by invoking | |
| 65 | // DefaultFn | |
| 66 | template <class Parameters, class Keyword, class DefaultFn> | |
| 67 | struct lazy_binding | |
| 68 | { | |
| 69 | typedef typename mpl::apply_wrap3< | |
| 70 | typename Parameters::binding | |
| 71 | , Keyword | |
| 72 | , typename aux::result_of0<DefaultFn>::type | |
| 73 | , mpl::true_ | |
| 74 | >::type type; | |
| 75 | }; | |
| 76 | ||
| 77 | ||
| 78 | }} // namespace boost::parameter | |
| 79 | ||
| 80 | #endif // BOOST_PARAMETER_BINDING_DWA200558_HPP |