1 | |
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2 | #ifndef BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED |
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3 | #define BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED |
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4 | |
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5 | // Copyright Aleksey Gurtovoy 2000-2008 |
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6 | // |
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7 | // Distributed under the Boost Software License, Version 1.0. |
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8 | // (See accompanying file LICENSE_1_0.txt or copy at |
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9 | // http://www.boost.org/LICENSE_1_0.txt) |
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10 | // |
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11 | // See http://www.boost.org/libs/mpl for documentation. |
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12 | |
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13 | // $Id: push_back_impl.hpp 55679 2009-08-20 07:50:16Z agurtovoy $ |
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14 | // $Date: 2009-08-20 03:50:16 -0400 (Thu, 20 Aug 2009) $ |
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15 | // $Revision: 55679 $ |
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16 | |
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17 | #include <boost/mpl/push_back_fwd.hpp> |
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18 | #include <boost/mpl/assert.hpp> |
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19 | #include <boost/mpl/aux_/has_type.hpp> |
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20 | #include <boost/mpl/aux_/traits_lambda_spec.hpp> |
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21 | #include <boost/mpl/aux_/config/forwarding.hpp> |
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22 | #include <boost/mpl/aux_/config/static_constant.hpp> |
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23 | |
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24 | #include <boost/type_traits/is_same.hpp> |
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25 | |
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26 | namespace boost { namespace mpl { |
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27 | |
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28 | struct has_push_back_arg {}; |
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29 | |
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30 | // agurt 05/feb/04: no default implementation; the stub definition is needed |
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31 | // to enable the default 'has_push_back' implementation below |
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32 | template< typename Tag > |
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33 | struct push_back_impl |
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34 | { |
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35 | template< typename Sequence, typename T > struct apply |
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36 | { |
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37 | // should be instantiated only in the context of 'has_push_back_impl'; |
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38 | // if you've got an assert here, you are requesting a 'push_back' |
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39 | // specialization that doesn't exist. |
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40 | BOOST_MPL_ASSERT_MSG( |
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41 | ( boost::is_same< T, has_push_back_arg >::value ) |
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42 | , REQUESTED_PUSH_BACK_SPECIALIZATION_FOR_SEQUENCE_DOES_NOT_EXIST |
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43 | , ( Sequence ) |
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44 | ); |
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45 | }; |
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46 | }; |
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47 | |
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48 | template< typename Tag > |
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49 | struct has_push_back_impl |
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50 | { |
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51 | template< typename Seq > struct apply |
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52 | #if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING) |
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53 | : aux::has_type< push_back< Seq, has_push_back_arg > > |
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54 | { |
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55 | #else |
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56 | { |
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57 | typedef aux::has_type< push_back< Seq, has_push_back_arg > > type; |
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58 | BOOST_STATIC_CONSTANT(bool, value = |
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59 | (aux::has_type< push_back< Seq, has_push_back_arg > >::value) |
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60 | ); |
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61 | #endif |
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62 | }; |
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63 | }; |
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64 | |
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65 | BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(2, push_back_impl) |
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66 | BOOST_MPL_ALGORITM_TRAITS_LAMBDA_SPEC(1, has_push_back_impl) |
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67 | |
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68 | }} |
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69 | |
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70 | #endif // BOOST_MPL_AUX_PUSH_BACK_IMPL_HPP_INCLUDED |
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