gecko-dev/mfbt/Opaque.h
Jeff Walden 1dd8dbc3f7 Bug 1246061. r=jandem, r=bz, r=luke, r=froydnj
--HG--
extra : rebase_source : 5b314d4c4c6e0b553290884be7338f8e79c22f71
2016-03-09 00:37:20 -08:00

45 lines
1.1 KiB
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/. */
/* An opaque integral type supporting only comparison operators. */
#ifndef mozilla_Opaque_h
#define mozilla_Opaque_h
#include "mozilla/TypeTraits.h"
namespace mozilla {
/**
* Opaque<T> is a replacement for integral T in cases where only comparisons
* must be supported, and it's desirable to prevent accidental dependency on
* exact values.
*/
template<typename T>
class Opaque final
{
static_assert(mozilla::IsIntegral<T>::value,
"mozilla::Opaque only supports integral types");
T mValue;
public:
Opaque() {}
explicit Opaque(T aValue) : mValue(aValue) {}
bool operator==(const Opaque& aOther) const {
return mValue == aOther.mValue;
}
bool operator!=(const Opaque& aOther) const {
return !(*this == aOther);
}
};
} // namespace mozilla
#endif /* mozilla_Opaque_h */