| // RUN: %clang_cc1 -std=c++1z -verify %s |
| |
| void use_from_own_init() { |
| auto [a] = a; // expected-error {{binding 'a' cannot appear in the initializer of its own decomposition declaration}} |
| } |
| |
| // As a Clang extension, _Complex can be decomposed. |
| float decompose_complex(_Complex float cf) { |
| static _Complex float scf; |
| auto &[sre, sim] = scf; |
| // ok, this is references initialized by constant expressions all the way down |
| static_assert(&sre == &__real scf); |
| static_assert(&sim == &__imag scf); |
| |
| auto [re, im] = cf; |
| return re*re + im*im; |
| } |
| |
| // As a Clang extension, vector types can be decomposed. |
| typedef float vf3 __attribute__((ext_vector_type(3))); |
| float decompose_vector(vf3 v) { |
| auto [x, y, z] = v; |
| auto *p = &x; // expected-error {{address of vector element requested}} |
| return x + y + z; |
| } |
| |
| struct S { int a, b; }; |
| constexpr int f(S s) { |
| auto &[a, b] = s; |
| return a * 10 + b; |
| } |
| static_assert(f({1, 2}) == 12); |
| |
| constexpr bool g(S &&s) { |
| auto &[a, b] = s; |
| return &a == &s.a && &b == &s.b && &a != &b; |
| } |
| static_assert(g({1, 2})); |
| |
| void enclosing() { |
| struct S { int a; }; |
| auto [n] = S(); // expected-note 2{{'n' declared here}} |
| |
| struct Q { int f() { return n; } }; // expected-error {{reference to local binding 'n' declared in enclosing function}} |
| // FIXME: This is probably supposed to be valid, but we do not have clear rules on how it's supposed to work. |
| (void) [&] { return n; }; // expected-error {{reference to local binding 'n' declared in enclosing function}} |
| (void) [n] {}; // expected-error {{'n' in capture list does not name a variable}} |
| } |
| |
| // FIXME: by-value array copies |