ceph/src/boost/boost/range/detail/has_member_size.hpp

   1 // Boost.Range library
   2 //
   3 // Copyright Neil Groves 2014.
   4 //
   5 // Use, modification and distribution are subject to the Boost Software License,
   6 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt).
   8 //
   9 // For more information, see http://www.boost.org/libs/range/
  10 //
  11 #ifndef BOOST_RANGE_DETAIL_HAS_MEMBER_SIZE_HPP
  12 #define BOOST_RANGE_DETAIL_HAS_MEMBER_SIZE_HPP
  13
  14 #include <boost/type_traits/is_class.hpp>
  15 #include <boost/type_traits/is_member_function_pointer.hpp>
  16 #include <boost/mpl/and.hpp>
  17 #include <boost/mpl/bool.hpp>
  18 #include <boost/cstdint.hpp>
  19
  20 namespace boost
  21 {
  22     namespace range_detail
  23     {
  24
  25 template<class T>
  26 class has_member_size_impl
  27 {
  28 private:
  29     template<class U, U>
  30     class check
  31     {
  32     };
  33
  34     template<class C>
  35     static boost::uint8_t f(check<std::size_t(C::*)(void) const, &C::size>*);
  36
  37     template<class C>
  38     static boost::uint16_t f(...);
  39
  40 public:
  41     static const bool value =
  42         (sizeof(f<T>(0)) == sizeof(boost::uint8_t));
  43
  44     typedef typename mpl::if_c<
  45         (sizeof(f<T>(0)) == sizeof(boost::uint8_t)),
  46         mpl::true_,
  47         mpl::false_
  48     >::type type;
  49 };
  50
  51 template<class T>
  52 struct has_member_size
  53 {
  54     typedef typename mpl::and_<
  55         typename is_class<T>::type,
  56         typename has_member_size_impl<const T>::type
  57     >::type type;
  58
  59     static const bool value =
  60         is_class<T>::value && has_member_size_impl<const T>::value;
  61 };
  62
  63     } // namespace range_detail
  64 }// namespace boost
  65
  66 #endif // include guard