TypeTraits.h

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#ifndef ZYPP_TYPETRAITS_H
#define ZYPP_TYPETRAITS_H
 
#include <type_traits>
 
namespace zypp
{
  namespace _detail
  {
    template<typename Tp>
    struct _has_type_const_iterator
    {
    private:
      template<typename C> static std::true_type  test( typename C::const_iterator * );
      template<typename C> static std::false_type test(...);
    public:
      static constexpr bool value = decltype(test<Tp>(nullptr))::value;
    };
 
    template <typename Tp>
    struct _has_container_begin_end
    {
    private:
      template <typename C>
      using Signature = typename C::const_iterator(C::*)() const;
 
      template<typename C> static std::true_type  testBeg( typename std::enable_if<std::is_same<decltype(static_cast<Signature<C>>(&C::begin)), Signature<C>>::value, void>::type* );
      template<typename C> static std::false_type testBeg(...);
 
      template<typename C> static std::true_type  testEnd( typename std::enable_if<std::is_same<decltype(static_cast<Signature<C>>(&C::end)), Signature<C>>::value,   void>::type* );
      template<typename C> static std::false_type testEnd(...);
 
    public:
      static constexpr bool beg_value = decltype(testBeg<Tp>(nullptr))::value;
      static constexpr bool end_value = decltype(testEnd<Tp>(nullptr))::value;
      static constexpr bool value = beg_value && end_value;
    };
  } // namespace _detail
 
  template<typename Tp>
  struct has_type_const_iterator
  : public std::integral_constant<bool, _detail::has_type_const_iterator<Tp>::value>
  {};
 
  template<typename Tp>
  struct has_container_begin_end
  : public std::integral_constant<bool, _detail::_has_container_begin_end<Tp>::value>
  {};
 
  template<typename Tp>
  struct is_container
  : public std::integral_constant<bool, !std::is_same<Tp, std::string>::value && has_container_begin_end<Tp>::value>
  {};
 
 
} // namespace zypp
#endif // ZYPP_TYPETRAITS_H