gecko-dev/mfbt/unused.h
Andrew McCreight c1e26ee03e Bug 1203314 - Make operator<< a method on unused_t. r=froydnj
This prevents operator overload resolution from failing when this file
is included in a file that uses Chromium IPC logging.

--HG--
extra : rebase_source : 661efe98060d405e87f828655b13c0c0a8a428e0
2015-09-10 13:17:00 +02:00

39 lines
970 B
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_unused_h
#define mozilla_unused_h
#include "mozilla/Types.h"
#ifdef __cplusplus
namespace mozilla {
//
// Suppress GCC warnings about unused return values with
// unused << SomeFuncDeclaredWarnUnusedReturnValue();
//
struct unused_t
{
template<typename T>
inline void
operator<<(const T& /*unused*/) const {}
};
extern MFBT_DATA const unused_t unused;
} // namespace mozilla
#endif // __cplusplus
// An alternative to mozilla::unused for use in (a) C code and (b) code where
// linking with unused.o is difficult.
#define MOZ_UNUSED(expr) \
do { if (expr) { (void)0; } } while (0)
#endif // mozilla_unused_h