C++程序  |  56行  |  2.5 KB

/*	$NetBSD: floatio.h,v 1.5 2005/05/14 23:51:02 christos Exp $	*/

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND 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 THE REGENTS OR 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.
 *
 *	@(#)floatio.h	8.1 (Berkeley) 6/4/93
 */

/*
 * Floating point scanf/printf (input/output) definitions.
 */

/* 11-bit exponent (VAX G floating point) is 308 decimal digits */
#define	MAXEXP		308
/* 128 bit fraction takes up 39 decimal digits; max reasonable precision */
#define	MAXFRACT	39
/*    
 * MAXEXPDIG is the maximum number of decimal digits needed to store a
 * floating point exponent in the largest supported format.  It should
 * be ceil(log10(LDBL_MAX_10_EXP)) or, if hexadecimal floating point 
 * conversions are supported, ceil(log10(LDBL_MAX_EXP)).  But since it
 * is presently never greater than 5 in practice, we fudge it.
 */   
#define MAXEXPDIG       6
#if LDBL_MAX_EXP > 999999
#error "floating point buffers too small"
#endif