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#ifndef ENTT_META_POLICY_HPP
#define ENTT_META_POLICY_HPP
#include <type_traits>
namespace entt {
/*! @brief Empty class type used to request the _as ref_ policy. */
struct as_ref_t final {
/*! @cond TURN_OFF_DOXYGEN */
template<typename Type>
static constexpr bool value = std::is_reference_v<Type> && !std::is_const_v<std::remove_reference_t<Type>>;
/*! @endcond */
};
/*! @brief Empty class type used to request the _as cref_ policy. */
struct as_cref_t final {
/*! @cond TURN_OFF_DOXYGEN */
template<typename Type>
static constexpr bool value = std::is_reference_v<Type>;
/*! @endcond */
};
/*! @brief Empty class type used to request the _as-is_ policy. */
struct as_is_t final {
/*! @cond TURN_OFF_DOXYGEN */
template<typename>
static constexpr bool value = true;
/*! @endcond */
};
/*! @brief Empty class type used to request the _as void_ policy. */
struct as_void_t final {
/*! @cond TURN_OFF_DOXYGEN */
template<typename>
static constexpr bool value = true;
/*! @endcond */
};
/**
* @brief Provides the member constant `value` to true if a type also is a meta
* policy, false otherwise.
* @tparam Type Type to check.
*/
template<typename Type>
struct is_meta_policy
: std::bool_constant<std::is_same_v<Type, as_ref_t> || std::is_same_v<Type, as_cref_t> || std::is_same_v<Type, as_is_t> || std::is_same_v<Type, as_void_t>> {};
/**
* @brief Helper variable template.
* @tparam Type Type to check.
*/
template<typename Type>
inline constexpr bool is_meta_policy_v = is_meta_policy<Type>::value;
} // namespace entt
#endif
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