src/boost/mpl/aux_/preprocessor/token_equal.hpp

   1
   2 #ifndef BOOST_MPL_AUX_PREPROCESSOR_TOKEN_EQUAL_HPP_INCLUDED
   3 #define BOOST_MPL_AUX_PREPROCESSOR_TOKEN_EQUAL_HPP_INCLUDED
   4
   5 // Copyright Paul Mensonides 2003
   6 // Copyright Aleksey Gurtovoy 2003-2004
   7 //
   8 // Distributed under the Boost Software License, Version 1.0.
   9 // (See accompanying file LICENSE_1_0.txt or copy at
  10 // http://www.boost.org/LICENSE_1_0.txt)
  11 //
  12 // See http://www.boost.org/libs/mpl for documentation.
  13
  14 // $Source: /cvsroot/boost/boost/boost/mpl/aux_/preprocessor/token_equal.hpp,v $
  15 // $Date: 2004/09/02 15:40:56 $
  16 // $Revision: 1.3 $
  17
  18 #include <boost/mpl/aux_/preprocessor/is_seq.hpp>
  19
  20 #include <boost/preprocessor/if.hpp>
  21 #include <boost/preprocessor/logical/bitand.hpp>
  22 #include <boost/preprocessor/logical/compl.hpp>
  23 #include <boost/preprocessor/tuple/eat.hpp>
  24 #include <boost/preprocessor/cat.hpp>
  25
  26 // compares tokens 'a' and 'b' for equality:
  27 //
  28 //   #define BOOST_MPL_PP_TOKEN_EQUAL_apple(x) x
  29 //   #define BOOST_MPL_PP_TOKEN_EQUAL_orange(x) x
  30 //
  31 //   BOOST_PP_ASSERT( BOOST_PP_NOT( BOOST_MPL_PP_TOKEN_EQUAL(apple, abc) ) )
  32 //   BOOST_PP_ASSERT( BOOST_PP_NOT( BOOST_MPL_PP_TOKEN_EQUAL(abc, apple) ) )
  33 //   BOOST_PP_ASSERT( BOOST_PP_NOT( BOOST_MPL_PP_TOKEN_EQUAL(apple, orange) ) )
  34 //   BOOST_PP_ASSERT( BOOST_MPL_PP_TOKEN_EQUAL(apple, apple) )
  35 //   BOOST_PP_ASSERT( BOOST_MPL_PP_TOKEN_EQUAL(orange, orange) )
  36
  37 #define BOOST_MPL_PP_TOKEN_EQUAL(a, b) \
  38     BOOST_PP_IIF( \
  39         BOOST_PP_BITAND( \
  40               BOOST_MPL_PP_IS_SEQ( BOOST_PP_CAT(BOOST_MPL_PP_TOKEN_EQUAL_, a)((unused)) ) \
  41             , BOOST_MPL_PP_IS_SEQ( BOOST_PP_CAT(BOOST_MPL_PP_TOKEN_EQUAL_, b)((unused)) ) \
  42             ) \
  43         , BOOST_MPL_PP_TOKEN_EQUAL_I \
  44         , 0 BOOST_PP_TUPLE_EAT(2) \
  45         )(a, b) \
  46 /**/
  47
  48 #define BOOST_MPL_PP_TOKEN_EQUAL_I(a, b) \
  49     BOOST_PP_COMPL(BOOST_MPL_PP_IS_SEQ( \
  50         BOOST_MPL_PP_TOKEN_EQUAL_ ## a( \
  51             BOOST_MPL_PP_TOKEN_EQUAL_ ## b \
  52             )((unused)) \
  53         )) \
  54 /**/
  55
  56 #endif // BOOST_MPL_AUX_PREPROCESSOR_TOKEN_EQUAL_HPP_INCLUDED