is_restricted_conversion.hpp 1.8 KB

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  1. ///////////////////////////////////////////////////////////////////////////////
  2. // Copyright Vicente J. Botet Escriba 2009-2011
  3. // Copyright 2012 John Maddock. Distributed under the Boost
  4. // Software License, Version 1.0. (See accompanying file
  5. // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  6. #ifndef BOOST_MP_RESTRICTED_CONVERSION_HPP
  7. #define BOOST_MP_RESTRICTED_CONVERSION_HPP
  8. #include <boost/multiprecision/traits/explicit_conversion.hpp>
  9. #include <boost/mpl/if.hpp>
  10. #include <boost/multiprecision/detail/number_base.hpp>
  11. namespace boost{ namespace multiprecision{ namespace detail{
  12. template <class From, class To>
  13. struct is_lossy_conversion
  14. {
  15. typedef typename mpl::if_c<
  16. ((number_category<From>::value == number_kind_floating_point) && (number_category<To>::value == number_kind_integer))
  17. || ((number_category<From>::value == number_kind_floating_point) && (number_category<To>::value == number_kind_rational))
  18. || ((number_category<From>::value == number_kind_rational) && (number_category<To>::value == number_kind_integer))
  19. || ((number_category<From>::value == number_kind_fixed_point) && (number_category<To>::value == number_kind_integer))
  20. || (number_category<From>::value == number_kind_unknown)
  21. || (number_category<To>::value == number_kind_unknown),
  22. mpl::true_,
  23. mpl::false_
  24. >::type type;
  25. static const bool value = type::value;
  26. };
  27. template<typename From, typename To>
  28. struct is_restricted_conversion
  29. {
  30. typedef typename mpl::if_c<
  31. ((is_explicitly_convertible<From, To>::value && !is_convertible<From, To>::value)
  32. || is_lossy_conversion<From, To>::value),
  33. mpl::true_,
  34. mpl::false_
  35. >::type type;
  36. static const bool value = type::value;
  37. };
  38. }}} // namespaces
  39. #endif // BOOST_MP_RESTRICTED_CONVERSION_HPP