1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// Make sure the rvalue overload of operator<< isn't part of the overload set
10// when the type is not output streamable into a lvalue stream.
11
12#include <ostream>
13#include <utility>
14
15struct Foo { };
16
17using X = decltype(std::declval<std::ostream>() << std::declval<Foo const&>()); // expected-error {{invalid operands to binary expression}}
18

source code of libcxx/test/std/input.output/iostream.format/output.streams/ostream.rvalue/not_ostreamable.verify.cpp