mfbt/NullPtr.h
author Sylvestre Ledru <sledru@mozilla.com>
Fri, 30 Nov 2018 11:46:48 +0100
changeset 508163 6f3709b3878117466168c40affa7bca0b60cf75b
parent 285938 91d6e262b662a0b4e47358665e222d3927337af9
permissions -rw-r--r--
Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format # ignore-this-changeset

/* -*- 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/. */

/* Implements a mozilla::IsNullPointer<T> type trait. */

#ifndef mozilla_NullPtr_h
#define mozilla_NullPtr_h

#include "mozilla/TypeTraits.h"

namespace mozilla {

/**
 * IsNullPointer<T>::value is true iff T is decltype(nullptr).
 *
 * Ideally this would be in TypeTraits.h, but C++11 omitted std::is_null_pointer
 * (fixed in C++14), so in the interests of easing a switch to <type_traits>,
 * this trait lives elsewhere.
 */
template <typename T>
struct IsNullPointer : FalseType {};

template <>
struct IsNullPointer<decltype(nullptr)> : TrueType {};

}  // namespace mozilla

#endif /* mozilla_NullPtr_h */