solanaceae_plugin/solanaceae/plugin/version_helper.inl

#pragma once

namespace internal {
	template<typename T>
	class g_type_version {
		typedef char yes[1];
		typedef char no [2];

		template<typename C> static yes& test_version(decltype(&C::version));
		template<typename C> static no& test_version(...);

		static bool const has_version = sizeof(test_version<T>(nullptr)) == sizeof(yes);
		static constexpr const char* get_version(void) {
			if constexpr (has_version) {
				return T::version;
			} else {
				return "UNK"; // default version
			}
		}

		public:
			static constexpr const char* version = get_version();
	};

	// more type support

	struct true_type {
		const static bool value {true};
	};
	struct false_type {
		const static bool value {false};
	};

	template<class T> struct is_pointer : false_type {};
	template<class T> struct is_pointer<T*> : true_type {};
	template<class T> struct is_pointer<T* const> : true_type {};
	template<class T> struct is_pointer<T* volatile> : true_type {};
	template<class T> struct is_pointer<T* const volatile> : true_type {};
} // internal