istream.cpp

pwlib源码库

        base = 0;

    if (ipfx(0))
    {
        c=bp->sgetc();
        for (i = 0; i<MAXLONGSIZ-1; buffer[i] = (char)c,c=bp->snextc(),i++)
        {
            if (c==EOF)
			{
                state |= ios::eofbit;
                break;
		    }
            if (!i)
			{
                if ((c=='-') || (c=='+'))
				{
                    bindex++;
                    continue;
				}
			}
            if ((i==bindex) && (buffer[i-1]== '0'))
			{
                if (((c=='x') || (c=='X')) && ((base==0) || (base==16)))
				{
                    base = 16;  // simplifies matters
                    fDigit = 0;
                    continue;
				}
                else if (base==0)
                {
                    base = 8;
				}
			}


            // now simply look for a digit and set fDigit if found else break
            if (base==16)
			{
                if (!_istxdigit(c))
                    break;
			}
            else if ((!_istdigit(c)) || ((base==8) && (c>'7')))
                break;

            fDigit++;
		}
        if (!fDigit)
		{
            state |= ios::failbit;
            while (i--)
			{
                if(bp->sputbackc(buffer[i])==EOF)
				{
                    state |= ios::badbit;
                    break;
				}
                else
                    state &= ~(ios::eofbit);
			}
            i=0;
		}
        // buffer contains a valid number or '\0'
        buffer[i] = '\0';
        isfx();
	}
    if (i==MAXLONGSIZ)
    {
        state |= ios::failbit;
	}
    return base;
}

/*******************************************************************************/
int     istream::getdouble(char* buffer, int buflen)   // returns length
{
    int c;
    int i = 0;
    int fDigit = 0;     // true if legal digit encountered
    int fDecimal=0;     // true if '.' encountered or no longer valid
    int fExp=0;         // true if 'E' or 'e' encounted

    if (ipfx(0))
    {
        c=bp->sgetc();
        for (; i<buflen; buffer[i] = c,c=bp->snextc(),i++)
		{
            if (c==EOF)
			{
                state |= ios::eofbit;
                break;
			}
            if ((!i) || (fExp==1))
			{
                if ((c=='-') || (c=='+'))
				{
                    continue;
				}
			}
            if ((c=='.') && (!fExp) && (!fDecimal))
			{
                fDecimal++;
                continue;
			}
            if (((c=='E') || (c=='e')) && (!fExp))
			{
                fDecimal++;     // can't allow decimal now
                fExp++;
                continue;
			}
            if (!_istdigit(c))
                break;
            if (fExp)
                fExp++;
            else
                fDigit++;
		}
        if (fExp==1)            // E or e with no number after it
		{
            if (bp->sputbackc(buffer[i])!=EOF)
			{
                i--;
                state &= ~(ios::eofbit);
			}
            else
			{
                state |= ios::failbit;
			}
		}
        if ((!fDigit) || (i==buflen))
            state |= ios::failbit;

        // buffer contains a valid number or '\0'
        buffer[i] = '\0';
        isfx();
	}
    return i;
}

/*******************************************************************************/
istream& istream::operator>>(char& c)
{
    int tchar;
    if (ipfx(0))
        {
        tchar=bp->sbumpc();
        if (tchar==EOF)
            {
            state |= ios::eofbit|ios::badbit;
            }
        else
            {
            c = (char)tchar;
            }
        isfx();
        }
    return *this;
}

/*******************************************************************************/
istream& istream::operator>>(short& n)
{
	char ibuffer[MAXLONGSIZ];
    long value;
    char** endptr = (char**)NULL;
    if (ipfx(0))
    {
        value = strtol(ibuffer, endptr, getint(ibuffer));
        if (value>SHRT_MAX)
		{
            n = SHRT_MAX;
            state |= ios::failbit;
		}
        else if (value<SHRT_MIN)
		{
            n = SHRT_MIN;
            state |= ios::failbit;
		}
        else
            n = (short) value;

        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(unsigned short& n)
{	
	char ibuffer[MAXLONGSIZ];
    unsigned long value;
    char** endptr = (char**)NULL;
    if (ipfx(0))
    {
        value = strtoul(ibuffer, endptr, getint(ibuffer));

        if ((value>USHRT_MAX) && (value<=(ULONG_MAX-(-SHRT_MIN))))
        {
			n = USHRT_MAX;
			state |= ios::failbit;
        }
        else
            n = (unsigned short) value;

        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(int& n)
{
	char ibuffer[MAXLONGSIZ];
    long value;
    char ** endptr = (char**)NULL;
    if (ipfx(0))
	{
        value = strtoul(ibuffer, endptr, getint(ibuffer));
        if (value>INT_MAX)
		{
            n = INT_MAX;
            state |= ios::failbit;
		}
        else if (value<INT_MIN)
        {
            n = INT_MIN;
            state |= ios::failbit;
        }
        else
            n = (int) value;

        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(unsigned int& n)
{
	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))))
		{
            n = UINT_MAX;
            state |= ios::failbit;
		}
        else
            n = (unsigned int) value;

        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(long& n)
{
	char ibuffer[MAXLONGSIZ];
    char ** endptr = (char**)NULL;
    if (ipfx(0)) 
	{
        n = strtoul(ibuffer, endptr, getint(ibuffer));
        isfx();
    }
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(unsigned long& n)
{
	char ibuffer[MAXLONGSIZ];
    char ** endptr = (char**)NULL;
    if (ipfx(0)) 
	{
        n = strtoul(ibuffer, endptr, getint(ibuffer));
        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(float& n)
{
	char ibuffer[MAXFLTSIZ];
    double d;
    char ** endptr = (char**)NULL;
    if (ipfx(0))
	{
        if (getdouble(ibuffer, MAXFLTSIZ)>0)
        {
            d = strtod(ibuffer, endptr);

            if (d > FLT_MAX)
                n = FLT_MAX;
            else if (d < -FLT_MAX)
                n =  -FLT_MAX;
            else if ((d>0) && (d< FLT_MIN))
                n = FLT_MIN;
            else if ((d<0) && (d> -FLT_MIN))
                n = - FLT_MIN;
            else
                n = (float) d;
		}
        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(double& n)
{
	char ibuffer[MAXDBLSIZ];
    char ** endptr = (char**)NULL;
    if (ipfx(0))
	{
        if (getdouble(ibuffer, MAXDBLSIZ)>0)
		{
            n = strtod(ibuffer, endptr);
		}
        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream& istream::operator>>(long double& n)
{
	char ibuffer[MAXLDBLSIZ];
    char** endptr = (char**)NULL;
    if (ipfx(0))
	{
        if (getdouble(ibuffer, MAXLDBLSIZ)>0)
		{
            n = (long double)strtod(ibuffer, endptr);
		}
        isfx();
	}
	return *this;
}

/*******************************************************************************/
istream_withassign::istream_withassign()
: istream()
{
}

/*******************************************************************************/
istream_withassign::istream_withassign(streambuf* _is)
: istream(_is)
{
}

/*******************************************************************************/
istream_withassign::~istream_withassign()
{
}