gcc/gcc/testsuite/g++.dg/concepts/class.C

53 lines
1.2 KiB
C

// { dg-options "-std=c++1z" }
template<typename T>
concept bool Class() { return __is_class(T); }
template<typename T>
concept bool Union() { return __is_union(T); }
// Check ordering of specializations
template<typename T>
concept bool One() { return sizeof(T) >= 4; }
template<typename T>
concept bool Two() { return One<T>() && sizeof(T) >= 8; }
// Check non-overlapping specializations
template<typename T>
struct S1 { static const int value = 0; };
template<Class T>
struct S1<T> { static const int value = 1; };
template<Union T>
struct S1<T> { static const int value = 2; };
struct S { };
union U { };
static_assert(S1<int>::value == 0, "");
static_assert(S1<S>::value == 1, "");
static_assert(S1<U>::value == 2, "");
// Check ordering of partial specializaitons
template<typename T>
struct S2 { static const int value = 0; };
template<One T>
struct S2<T> { static const int value = 1; };
template<Two T>
struct S2<T> { static const int value = 2; };
struct one_type { char x[4]; };
struct two_type { char x[8]; };
static_assert(S2<char>::value == 0, "");
static_assert(S2<one_type>::value == 1, "");
static_assert(S2<two_type>::value == 2, "");
int main() { }