gecko-dev/xpcom/ds/nsStaticAtomUtils.h

40 строки
1.2 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/. */
#ifndef nsStaticAtomUtils_h
#define nsStaticAtomUtils_h
#include <stdint.h>
#include "nsAtom.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/Maybe.h"
// This class holds basic operations on arrays of static atoms.
class nsStaticAtomUtils
{
public:
static mozilla::Maybe<uint32_t> Lookup(nsAtom* aAtom,
const nsStaticAtom* aAtoms,
uint32_t aCount)
{
if (aAtom->IsStatic()) {
ptrdiff_t index = aAtom->AsStatic() - aAtoms;
if (index >= 0 && index < static_cast<ptrdiff_t>(aCount)) {
return mozilla::Some(static_cast<uint32_t>(index));
}
}
return mozilla::Nothing();
}
static bool IsMember(nsAtom* aAtom, const nsStaticAtom* aAtoms,
uint32_t aCount)
{
return Lookup(aAtom, aAtoms, aCount).isSome();
}
};
#endif // nsStaticAtomUtils_h