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# simple_number.h

    00001 // -*- c-basic-offset: 2 -*-
    00002 /*
    00003  *  This file is part of the KDE libraries
    00004  *  Copyright (C) 2003 Apple Computer, Inc
    00005  *
    00006  *  This library is free software; you can redistribute it and/or
    00007  *  modify it under the terms of the GNU Library General Public
    00008  *  License as published by the Free Software Foundation; either
    00009  *  version 2 of the License, or (at your option) any later version.
    00010  *
    00011  *  This library is distributed in the hope that it will be useful,
    00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00014  *  Library General Public License for more details.
    00015  *
    00016  *  You should have received a copy of the GNU Library General Public License
    00017  *  along with this library; see the file COPYING.LIB.  If not, write to
    00018  *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00019  *  Boston, MA 02111-1307, USA.
    00020  *
    00021  */
    00022
    00023 #ifndef _KJS_SIMPLE_NUMBER_H_
    00024 #define _KJS_SIMPLE_NUMBER_H_
    00025
    00026 #include <limits.h>
    00027 #include <math.h>
    00028 #include <string.h>
    00029
    00030 #define IS_NEGATIVE_ZERO(num) (num == 0.0 && !memcmp(&num,&SimpleNumber::negZero,sizeof(double)))
    00031
    00032 namespace KJS {
    00033     class ValueImp;
    00034
    00035     class SimpleNumber {
    00036     public:
    00037     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 };
    00038
    00039     static inline bool is(const ValueImp *imp) { return ((long)imp & mask) == tag; }
    00040     static inline long value(const ValueImp *imp) { return ((long)imp >> shift) | (((long)imp & sign) ? ~max : 0); }
    00041
    00042     static inline bool fits(int i) { return i <= imax && i >= imin; }
    00043     static inline bool fits(unsigned i) { return i <= (unsigned)max; }
    00044     static inline bool fits(long i) { return i <= max && i >= min; }
    00045     static inline bool fits(unsigned long i) { return i <= (unsigned)max; }
    00046     static inline bool fits(double d) { return d <= max && d >= min && d == (double)(long)d &&
    00047                         !IS_NEGATIVE_ZERO(d); }
    00048     static inline ValueImp *make(long i) { return (ValueImp *)((i << shift) | tag); }
    00049
    00050     static double negZero;
    00051
    00052     };
    00053 }
    00054
    00055 #endif

This file is part of the documentation for kjs Library Version 3.4.1.
Documentation copyright © 1996-2004 the KDE developers.
Generated on Sat Jun 11 20:23:07 2005 by doxygen 1.4.1 written by Dimitri van Heesch, © 1997-2003