ceph/src/boost/libs/spirit/include/boost/spirit/home/x3/support/utility/sfinae.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3     Copyright (c) 2013 Agustin Berge
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(BOOST_SPIRIT_X3_SFINAE_MAY_20_2013_0840AM)
   9 #define BOOST_SPIRIT_X3_SFINAE_MAY_20_2013_0840AM
  10
  11 namespace boost { namespace spirit { namespace x3
  12 {
  13     template <typename Expr, typename T = void>
  14     struct disable_if_substitution_failure
  15     {
  16         typedef T type;
  17     };
  18
  19     template <typename Expr, typename T>
  20     struct lazy_disable_if_substitution_failure
  21     {
  22         typedef typename T::type type;
  23     };
  24 }}}
  25
  26 #endif