toml11/toml/traits.hpp
2017-04-21 13:14:53 +09:00

55 lines
1.5 KiB
C++

#ifndef TOML11_TRAITS
#define TOML11_TRAITS
#include <type_traits>
namespace toml
{
namespace detail
{
template<typename T>
using unwrap_t = typename std::decay<T>::type;
struct has_iterator_impl
{
template<typename T> static std::true_type check(typename T::iterator*);
template<typename T> static std::false_type check(...);
};
struct has_value_type_impl
{
template<typename T> static std::true_type check(typename T::value_type*);
template<typename T> static std::false_type check(...);
};
struct has_key_type_impl
{
template<typename T> static std::true_type check(typename T::key_type*);
template<typename T> static std::false_type check(...);
};
struct has_mapped_type_impl
{
template<typename T> static std::true_type check(typename T::mapped_type*);
template<typename T> static std::false_type check(...);
};
template<typename T>
struct has_iterator : decltype(has_iterator_impl::check<T>(nullptr)){};
template<typename T>
struct has_value_type : decltype(has_value_type_impl::check<T>(nullptr)){};
template<typename T>
struct has_key_type : decltype(has_key_type_impl::check<T>(nullptr)){};
template<typename T>
struct has_mapped_type : decltype(has_mapped_type_impl::check<T>(nullptr)){};
template<typename T>
struct is_container : std::integral_constant<bool,
has_iterator<T>::value && has_value_type<T>::value>{};
template<typename T>
struct is_map : std::integral_constant<bool,
has_iterator<T>::value && has_key_type<T>::value &&
has_mapped_type<T>::value>{};
}// detail
}//toml
#endif // TOML_TRAITS