P0217R3: Perform semantic checks and initialization for the bindings in a

decomposition declaration for arrays, aggregate-like structs, tuple-like
types, and (as an extension) for complex and vector types.

llvm-svn: 278435

1 files changed, 17 insertions, 1 deletions

diff --git a/clang/test/SemaCXX/cxx1z-decomposition.cpp b/clang/test/SemaCXX/cxx1z-decomposition.cpp
index 53434771ac7..6541476a67b 100644
--- a/clang/test/SemaCXX/cxx1z-decomposition.cpp
+++ b/clang/test/SemaCXX/cxx1z-decomposition.cpp
@@ -4,7 +4,23 @@ void use_from_own_init() {
   auto [a] = a; // expected-error {{binding 'a' cannot appear in the initializer of its own decomposition declaration}}
 }
 
-// FIXME: create correct bindings
+// As a Clang extension, _Complex can be decomposed.
+float decompose_complex(_Complex float cf) {
+  auto [re, im] = cf;
+  //static_assert(&re == &__real cf);
+  //static_assert(&im == &__imag 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;
+}
+
+// FIXME: by-value array copies
 // FIXME: template instantiation
 // FIXME: ast file support
 // FIXME: code generation