mfbt/unused.h
author Xidorn Quan <me@upsuper.org>
Wed, 13 Jul 2016 09:01:25 +1000
changeset 305792 875e441f8b804adaf67ad704171c8b2f04015499
parent 270717 7ec70e0c699746cf72e03acadc09d0d5877423d0
permissions -rw-r--r--
Bug 1286089 - Ensure servo can be linked properly for different compilers. r=glandium MozReview-Commit-ID: 71NofEtZx6B

/* -*- 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