allegro + hex integers

CamelofCamelot · 01-02-2004, 08:59 PM

How, in C++, do I save a hex value to an integer?

I would like to read in hex values from a file opened w/ ios::hex|ios::in. ios::hex is correct, neh?

Also, what options does g++ need to compile an allegro program.

CamelofCamelot · 01-03-2004, 02:52 AM

Nevermind on the allegro thing, I managed to find the answer (search: -lalleg), which was close enough to the real thing

but how does one save hex values to an integer?

Hko · 01-03-2004, 08:29 AM

Code:

#include <iostream>
#include <sstream>

int main()
{
     int intvalue;
     string hexstr = "FF";
     istringstream istr(hexstr);

     istr.setf(ios::hex, ios::basefield);
     istr >> intvalue;

     std::cout << hexstr << " in decimal is: " << intvalue << std::endl;
     return 0;
}

CamelofCamelot · 01-03-2004, 12:34 PM

That appears to be just formatting a decimal int as hex for cout. I'd like to be able to do something like:
for(int i=0; i<FF; i++) or something

OH! is it

for(int i=0x00; i<0xFF; i++) ?? would that work?

Nevermind, I found a way to do it w/out using hex.

Hko · 01-04-2004, 09:56 AM

Quote:

Originally posted by CamelofCamelot
That appears to be just formatting a decimal int as hex for cout.

No, it's not.
It is reading as string formatted as hex into a integer.
Have a look at the code. The integer intvalue gets the value 255 as translated from the string hexstr which is "FF". After that it is printed with cout.

Quote:

Originally posted by CamelofCamelot
OH! is it

for(int i=0x00; i<0xFF; i++) ?? would that work?

Yes, that should work.