widest_char.hpp 1.4 KB

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  1. // Copyright Kevlin Henney, 2000-2005.
  2. // Copyright Alexander Nasonov, 2006-2010.
  3. // Copyright Antony Polukhin, 2011-2019.
  4. //
  5. // Distributed under the Boost Software License, Version 1.0. (See
  6. // accompanying file LICENSE_1_0.txt or copy at
  7. // http://www.boost.org/LICENSE_1_0.txt)
  8. //
  9. // what: lexical_cast custom keyword cast
  10. // who: contributed by Kevlin Henney,
  11. // enhanced with contributions from Terje Slettebo,
  12. // with additional fixes and suggestions from Gennaro Prota,
  13. // Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
  14. // Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann,
  15. // Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters
  16. // when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014
  17. #ifndef BOOST_LEXICAL_CAST_DETAIL_WIDEST_CHAR_HPP
  18. #define BOOST_LEXICAL_CAST_DETAIL_WIDEST_CHAR_HPP
  19. #include <boost/config.hpp>
  20. #ifdef BOOST_HAS_PRAGMA_ONCE
  21. # pragma once
  22. #endif
  23. #include <boost/type_traits/conditional.hpp>
  24. namespace boost { namespace detail {
  25. template <typename TargetChar, typename SourceChar>
  26. struct widest_char {
  27. typedef BOOST_DEDUCED_TYPENAME boost::conditional<
  28. (sizeof(TargetChar) > sizeof(SourceChar))
  29. , TargetChar
  30. , SourceChar
  31. >::type type;
  32. };
  33. }} // namespace boost::detail
  34. #endif // BOOST_LEXICAL_CAST_DETAIL_WIDEST_CHAR_HPP