/* -*- 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 */