type_traits.hxx

#pragma once
 
#include <optional>
#include <type_traits>
 
namespace StormByte {
    template<typename T, typename _ = void>
    struct is_container : std::false_type {};
 
    template<typename T>
    struct is_container<T, std::void_t<decltype(std::declval<T>().begin()), decltype(std::declval<T>().end()), typename T::value_type>> : std::true_type {};
 
    template<typename T, typename _ = void>
    struct is_optional : std::false_type {};
 
    template<typename T>
    struct is_optional<T, std::void_t<typename T::value_type>> 
        : std::is_same<T, std::optional<typename T::value_type>> {};
 
    template<typename T, typename _ = void>
    struct is_pair : std::false_type {};
 
    template<typename T>
    struct is_pair<T, std::void_t<
        decltype(std::declval<T>().first), 
        decltype(std::declval<T>().second)
    >> : std::true_type {};
 
    template <typename T>
    struct is_reference {
        static constexpr bool value = std::is_reference_v<T>;
    };
}