2 #ifndef BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED
3 #define BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED
5 // Copyright Aleksey Gurtovoy 2000-2008
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)
11 // See http://www.boost.org/libs/mpl for documentation.
13 // $Id: push_back_impl.hpp 55679 2009-08-20 07:50:16Z agurtovoy $
14 // $Date: 2009-08-20 00:50:16 -0700 (Thu, 20 Aug 2009) $
17 #include <boost/mpl/push_back_fwd.hpp>
18 #include <boost/mpl/assert.hpp>
19 #include <boost/mpl/aux_/has_type.hpp>
20 #include <boost/mpl/aux_/traits_lambda_spec.hpp>
21 #include <boost/mpl/aux_/config/forwarding.hpp>
22 #include <boost/mpl/aux_/config/static_constant.hpp>
24 #include <boost/type_traits/is_same.hpp>
26 namespace boost { namespace mpl {
28 struct has_push_back_arg {};
30 // agurt 05/feb/04: no default implementation; the stub definition is needed
31 // to enable the default 'has_push_back' implementation below
32 template< typename Tag >
35 template< typename Sequence, typename T > struct apply
37 // should be instantiated only in the context of 'has_push_back_impl';
38 // if you've got an assert here, you are requesting a 'push_back'
39 // specialization that doesn't exist.
41 ( boost::is_same< T, has_push_back_arg >::value )
42 , REQUESTED_PUSH_BACK_SPECIALIZATION_FOR_SEQUENCE_DOES_NOT_EXIST
48 template< typename Tag >
49 struct has_push_back_impl
51 template< typename Seq > struct apply
52 #if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)
53 : aux::has_type< push_back< Seq, has_push_back_arg > >
57 typedef aux::has_type< push_back< Seq, has_push_back_arg > > type;
58 BOOST_STATIC_CONSTANT(bool, value =
59 (aux::has_type< push_back< Seq, has_push_back_arg > >::value)
65 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(2, push_back_impl)
66 BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1, has_push_back_impl)
70 #endif // BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED