/* * Copyright (C) 2010, Google Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #pragma once namespace WTF { // An abstract number of element in a sequence. The sequence has a first element. // This type should be used instead of integer because 2 contradicting traditions can // call a first element '0' or '1' which makes integer type ambiguous. class OrdinalNumber { public: static OrdinalNumber beforeFirst() { return OrdinalNumber(-1); } static OrdinalNumber fromZeroBasedInt(int zeroBasedInt) { return OrdinalNumber(zeroBasedInt); } static OrdinalNumber fromOneBasedInt(int oneBasedInt) { return OrdinalNumber(oneBasedInt - 1); } OrdinalNumber() : m_zeroBasedValue(0) { } int zeroBasedInt() const { return m_zeroBasedValue; } int oneBasedInt() const { return m_zeroBasedValue + 1; } bool operator==(OrdinalNumber other) const { return m_zeroBasedValue == other.m_zeroBasedValue; } bool operator!=(OrdinalNumber other) const { return !((*this) == other); } bool operator>(OrdinalNumber other) const { return m_zeroBasedValue > other.m_zeroBasedValue; } private: OrdinalNumber(int zeroBasedInt) : m_zeroBasedValue(zeroBasedInt) { } int m_zeroBasedValue; }; } using WTF::OrdinalNumber;