windows-server-2003/base/crts/crtw32/iostream/istruint.cpp

/***
* istruint.cpp - definitions for istream class operaotor>>(unsigned int) funct
*
*	Copyright (c) 1991-2001, Microsoft Corporation.  All rights reserved.
*
*Purpose:
*	Definitions of operator>>(unsigned int) member function for istream
*	class.
*	[AT&T C++]
*
*Revision History:
*       09-26-91  KRS   Created.  Split out from istream.cxx for granularity.
*       01-06-92  KRS   Improve error handling.
*       12-30-92  KRS   Fix indirection problem with **endptr.
*       12-16-92  CFW   Cast to get rid of compiler warning.
*       05-24-94  GJF   Moved definition of MAXLONGSIZ to istream.h.
*       06-14-95  CFW   Comment cleanup.
*
*******************************************************************************/

#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <iostream.h>
#pragma hdrstop

/***
*istream& istream::operator>>(unsigned int& n) - extract unsigned int
*
*Purpose:
*	Extract unsigned int value from stream
*	Valid range is INT_MIN to UINT_MAX.
*
*Entry:
*	n = value to update
*
*Exit:
*	n updated, or ios::failbit and n=UINT_MAX if error
*
*Exceptions:
*	Stream error on entry or value out of range
*
*******************************************************************************/
istream& istream::operator>>(unsigned int& n)
{
_WINSTATIC char ibuffer[MAXLONGSIZ];
    unsigned long value;
    char ** endptr = (char**)NULL;
    if (ipfx(0)) {
	value = strtoul(ibuffer, endptr, getint(ibuffer));

	if (((value>UINT_MAX) && (value<=(ULONG_MAX-(unsigned long)(-INT_MIN))))
		|| ((value==ULONG_MAX) && (errno==ERANGE)))
	    {
	    n = UINT_MAX;
	    state |= ios::failbit;
	    }
	else
	    n = (unsigned int) value;

        isfx();
	}
return *this;
}