#ifndef __GBLIBCPP_UTILITY__
#define __GBLIBCPP_UTILITY__

#include <type_traits>

namespace std {

template <typename T>
constexpr remove_reference_t<T>&& move(T&& val)
{
    return static_cast<remove_reference_t<T>&&>(val);
}

template <typename T>
constexpr T&& forward(remove_reference_t<T>& val)
{
    return static_cast<T&&>(val);
}
template <typename T>
constexpr T&& forward(remove_reference_t<T>&& val)
{
    return static_cast<T&&>(val);
}

template <typename T, typename U = T>
constexpr T exchange(T& dst, U&& val)
{
    T tmp = move(dst);
    dst = forward<U>(val);
    return tmp;
}

} // namespace std

#endif