sfinae.hpp 842 B

1234567891011121314151617181920212223242526
  1. /*=============================================================================
  2. Copyright (c) 2001-2014 Joel de Guzman
  3. Copyright (c) 2013 Agustin Berge
  4. Distributed under the Boost Software License, Version 1.0. (See accompanying
  5. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  6. ==============================================================================*/
  7. #if !defined(BOOST_SPIRIT_X3_SFINAE_MAY_20_2013_0840AM)
  8. #define BOOST_SPIRIT_X3_SFINAE_MAY_20_2013_0840AM
  9. namespace boost { namespace spirit { namespace x3
  10. {
  11. template <typename Expr, typename T = void>
  12. struct disable_if_substitution_failure
  13. {
  14. typedef T type;
  15. };
  16. template <typename Expr, typename T>
  17. struct lazy_disable_if_substitution_failure
  18. {
  19. typedef typename T::type type;
  20. };
  21. }}}
  22. #endif