mfbt/Unused.h
author Brian Birtles <birtles@gmail.com>
Wed, 06 Mar 2019 10:34:30 +0000
changeset 464601 52a879d4e479200bddbe0bf3ee6b4c28e7d220de
parent 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1528894 [wpt PR 15455] - [html] Add test that cancelAnimationFrame cancels a pending animation frame callback, a=testonly Automatic update from web-platform-tests HTML: cancelAnimationFrame cancels a pending animation frame callback For https://github.com/whatwg/html/pull/4375. -- wpt-commits: bbbe615d3f5b7b44ed49b4b369f19d4c5dd32e53 wpt-pr: 15455

/* -*- 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/Attributes.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>
  MOZ_ALWAYS_INLINE_EVEN_DEBUG 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