[thirdparty/gcc.git] / gcc / testsuite / g++.dg / cpp0x / sfinae52.C

// PR c++/62072
// { dg-do compile { target c++11 } }

template<typename T> struct tuple_size {};
template<typename T> struct tuple_size<T const> : tuple_size<T> {};

template<typename T, typename = void>
struct query {
    static constexpr bool value = false;
};
template<typename T>
struct query<T, typename tuple_size<T>::type> {
    static constexpr bool value = true;
};

// fine
static_assert( !query<int>::value, "" );
static_assert( !query<int const>::value, "" );

// error: invalid use of incomplete type 'struct tuple_size<void()>'
static_assert( !query<void()>::value, "" );
Commit	Line	Data
	1	// PR c++/62072
	2	// { dg-do compile { target c++11 } }
	3
	4	template<typename T> struct tuple_size {};
	5	template<typename T> struct tuple_size<T const> : tuple_size<T> {};
	6
	7	template<typename T, typename = void>
	8	struct query {
	9	static constexpr bool value = false;
	10	};
	11	template<typename T>
	12	struct query<T, typename tuple_size<T>::type> {
	13	static constexpr bool value = true;
	14	};
	15
	16	// fine
	17	static_assert( !query<int>::value, "" );
	18	static_assert( !query<int const>::value, "" );
	19
	20	// error: invalid use of incomplete type 'struct tuple_size<void()>'
	21	static_assert( !query<void()>::value, "" );