is_specialization.h

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#ifndef MYSQL_META_IS_SPECIALIZATION_H
#define MYSQL_META_IS_SPECIALIZATION_H
 
/// @file
/// Experimental API header
 
#include <type_traits>
 
/// @addtogroup GroupLibsMysqlMeta
/// @{
 
namespace mysql::meta::detail {
 
/// @brief Helper struct used to determine at compile time
/// whether a given type Test is a template specialization of the Primary
template <typename Test, template <typename...> class Primary>
struct Is_specialization_helper : std::false_type {};
 
/// @brief Helper struct used to determine at compile time
/// whether a given type Test is a template specialization of the Primary
template <template <typename...> class Primary, typename... Args>
struct Is_specialization_helper<Primary<Args...>, Primary> : std::true_type {};
 
/// @brief Helper struct used to determine at compile time whether a given type
/// Test is a template specialization of the Primary, where all template
/// arguments are non-types.
template <typename Test, template <auto...> class Primary>
struct Is_nontype_specialization_helper : std::false_type {};
 
/// @brief Helper struct used to determine at compile time whether a given type
/// Test is a template specialization of the Primary, where all template
/// arguments are non-types.
template <template <auto...> class Primary, auto... Args>
struct Is_nontype_specialization_helper<Primary<Args...>, Primary>
    : std::true_type {};
 
}  // namespace mysql::meta::detail
 
namespace mysql::meta {
 
/// @brief Concept used to determine at compile time whether a given type Test
/// is a template specialization of the Primary. This works if all template
/// arguments of Primary are types (not constants/non-types).
template <class Test, template <typename...> class Primary>
concept Is_specialization =
    detail::Is_specialization_helper<Test, Primary>::value;
 
/// @brief Concept used to determine at compile time whether a given type Test
/// is a template specialization of the Primary. This works if all template
/// arguments of Primary are constants/non-types (not types).
template <class Test, template <auto...> class Primary>
concept Is_nontype_specialization =
    detail::Is_nontype_specialization_helper<Test, Primary>::value;
 
}  // namespace mysql::meta
 
/// @}
 
#endif  // MYSQL_META_IS_SPECIALIZATION_H