simple_number.h
// -*- c-basic-offset: 2 -*-
/*
* This file is part of the KDE libraries
* Copyright (C) 2003 Apple Computer, Inc
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef _KJS_SIMPLE_NUMBER_H_
#define _KJS_SIMPLE_NUMBER_H_
#include <math.h>
#include <string.h>
#define IS_NEGATIVE_ZERO(num) (num == 0.0 && !memcmp(&num, &SimpleNumber::negZero, sizeof(double)))
namespace KJS {
class ValueImp;
class SimpleNumber {
public:
enum { tag = 1, shift = 2, mask = (1 << shift) - 1, sign = 1L << (sizeof(long) * 8 - 1 ), max = (1L << ((sizeof(long) * 8 - 1) - shift)) - 1, min = -max - 1, imax = (1L << ((sizeof(int) * 8 - 1) - shift)) - 1, imin = -imax - 1 };
static inline bool is(const ValueImp *imp) { return ((long)imp & mask) == tag; }
static inline long value(const ValueImp *imp) { return ((long)imp >> shift) | (((long)imp & sign) ? ~max : 0); }
static inline bool fits(int i) { return i <= imax && i >= imin; }
static inline bool fits(unsigned i) { return i <= (unsigned)max; }
static inline bool fits(long i) { return i <= max && i >= min; }
static inline bool fits(unsigned long i) { return i <= (unsigned)max; }
static inline bool fits(double d) { return d >= min && d <= max && d == (double)(long)d && !IS_NEGATIVE_ZERO(d); }
static inline ValueImp *make(long i) { return (ValueImp *)((i << shift) | tag); }
static double negZero;
};
}
#endif

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