Symaptic: os/ossrv/ossrv_pub/boost_apis/boost/mpl/if.hpp@260cb5ec6c19

     2 #ifndef BOOST_MPL_IF_HPP_INCLUDED

     3 #define BOOST_MPL_IF_HPP_INCLUDED

     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.

    13 // $Source: /cvsroot/boost/boost/boost/mpl/if.hpp,v $

    14 // $Date: 2004/09/07 08:51:31 $

    15 // $Revision: 1.25 $

    17 #include <boost/mpl/aux_/value_wknd.hpp>

    18 #include <boost/mpl/aux_/static_cast.hpp>

    19 #include <boost/mpl/aux_/na_spec.hpp>

    20 #include <boost/mpl/aux_/lambda_support.hpp>

    21 #include <boost/mpl/aux_/config/integral.hpp>

    22 #include <boost/mpl/aux_/config/ctps.hpp>

    23 #include <boost/mpl/aux_/config/workaround.hpp>

    25 namespace boost { namespace mpl {

    27 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)

    29 template<

    30       bool C

    31     , typename T1

    32     , typename T2

    33     >

    34 struct if_c

    35 {

    36     typedef T1 type;

    37 };

    39 template<

    40       typename T1

    41     , typename T2

    42     >

    43 struct if_c<false,T1,T2>

    44 {

    45     typedef T2 type;

    46 };

    48 // agurt, 05/sep/04: nondescriptive parameter names for the sake of DigitalMars

    49 // (and possibly MWCW < 8.0); see http://article.gmane.org/gmane.comp.lib.boost.devel/108959

    50 template<

    51       typename BOOST_MPL_AUX_NA_PARAM(T1)

    52     , typename BOOST_MPL_AUX_NA_PARAM(T2)

    53     , typename BOOST_MPL_AUX_NA_PARAM(T3)

    54     >

    55 struct if_

    56 {

    57  private:

    58     // agurt, 02/jan/03: two-step 'type' definition for the sake of aCC

    59     typedef if_c<

    60 #if defined(BOOST_MPL_CFG_BCC_INTEGRAL_CONSTANTS)

    61           BOOST_MPL_AUX_VALUE_WKND(T1)::value

    62 #else

    63           BOOST_MPL_AUX_STATIC_CAST(bool, BOOST_MPL_AUX_VALUE_WKND(T1)::value)

    64 #endif

    65         , T2

    66         , T3

    67         > almost_type_;

    69  public:

    70     typedef typename almost_type_::type type;

    72     BOOST_MPL_AUX_LAMBDA_SUPPORT(3,if_,(T1,T2,T3))

    73 };

    75 #else

    77 // no partial class template specialization

    79 namespace aux {

    81 template< bool C >

    82 struct if_impl

    83 {

    84     template< typename T1, typename T2 > struct result_

    85     {

    86         typedef T1 type;

    87     };

    88 };

    90 template<>

    91 struct if_impl<false>

    92 {

    93     template< typename T1, typename T2 > struct result_

    94     {

    95         typedef T2 type;

    96     };

    97 };

    99 } // namespace aux

   101 template<

   102       bool C_

   103     , typename T1

   104     , typename T2

   105     >

   106 struct if_c

   107 {

   108     typedef typename aux::if_impl< C_ >

   109         ::template result_<T1,T2>::type type;

   110 };

   112 // (almost) copy & paste in order to save one more

   113 // recursively nested template instantiation to user

   114 template<

   115       typename BOOST_MPL_AUX_NA_PARAM(C_)

   116     , typename BOOST_MPL_AUX_NA_PARAM(T1)

   117     , typename BOOST_MPL_AUX_NA_PARAM(T2)

   118     >

   119 struct if_

   120 {

   121     enum { msvc_wknd_ = BOOST_MPL_AUX_MSVC_VALUE_WKND(C_)::value };

   123     typedef typename aux::if_impl< BOOST_MPL_AUX_STATIC_CAST(bool, msvc_wknd_) >

   124         ::template result_<T1,T2>::type type;

   126     BOOST_MPL_AUX_LAMBDA_SUPPORT(3,if_,(C_,T1,T2))

   127 };

   129 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

   131 BOOST_MPL_AUX_NA_SPEC(3, if_)

   133 }}

   135 #endif // BOOST_MPL_IF_HPP_INCLUDED

author	sl
	Tue, 10 Jun 2014 14:32:02 +0200
changeset 1	260cb5ec6c19
permissions	-rw-r--r--