llvm-project/clang/test/SemaTemplate/cxx1z-decomposition.cpp

34 lines
876 B
C++

// RUN: %clang_cc1 -std=c++1z -verify %s
struct A { int x, y; };
typedef int B[2];
struct C { template<int> int get(); };
struct D { int x, y, z; };
struct E { int *p, n; };
namespace std {
using size_t = decltype(sizeof(0));
template<typename> struct tuple_size;
template<size_t, typename> struct tuple_element { using type = int; };
}
template<> struct std::tuple_size<C> { enum { value = 2 }; };
template<typename T> int decomp(T &t) {
auto &[a, b] = t; // expected-error {{type 'D' decomposes into 3 elements, but only 2 names were provided}}
return a + b; // expected-error {{cannot initialize return object of type 'int' with an rvalue of type 'int *'}}
}
void test() {
A a;
B b;
C c;
D d;
E e;
decomp(a);
decomp(b);
decomp(c);
decomp(d); // expected-note {{in instantiation of}}
decomp(e); // expected-note {{in instantiation of}}
}