llvm-project/clang/test/SemaCXX/cast-lvalue-to-rvalue-refer...

// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
// expected-no-diagnostics

struct S {};
int x;
S&& y1 = (S&&)x;
S&& y2 = reinterpret_cast<S&&>(x);
S& z1 = (S&)x;
[Sema] If lvalue to rvalue reference cast is valid don't emit diagnostic. In the test, y1 is not reference compatible to y2 and we currently assume the cast is ill-formed so we emit a diagnostic. Instead, in order to honour the standard, if y1 it's not reference-compatible to y2 then it can't be converted using a static_cast, and a reinterpret_cast should be tried instead. Richard Smith provided the correct interpretation of the standard and explanation about the subtle difference between "can't be cast" and "the cast is ill-formed". The former applies in this case. PR: 23802 llvm-svn: 241998 2015-07-13 06:10:56 +08:00			`// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11`
			`// expected-no-diagnostics`

			`struct S {};`
			`int x;`
			`S&& y1 = (S&&)x;`
			`S&& y2 = reinterpret_cast<S&&>(x);`
			`S& z1 = (S&)x;`