[Clex]

Here's mine :

    $ cat test.c
    #include <stdio.h>
    
    int main() {
        int a = 3;
        int b = 3;
    
        // aren't we supposed to add 2 and 2 ??/
        a = 2;
        b = 2;
    
        printf("%d\n", a + b);
    
        return 0;
    }
    $ gcc -W -Wall -trigraphs test2.c 2>/dev/null
    $ ./a.out
    5
    $

[gizmo686]

Is the trick here the "-trigraphs" flag, or the fact that you are showing us test.c but compiling test2.c? Both approaches seem like they should work.

[cdcarter]

It's the trigraph ??/ which translates to a \.

[gizmo686]

The trigraph appears in the file "test.c". If you look at the compilation command, you will see that that is not the file that is actually compiled.

[cbsmith]

If you compile "test.c" you will see that that isn't relevant issue.

[tbirdz]

Very sneaky. For anyone else wondering why this works, look up trigraphs.

[vidarh]

And after looking it up, you better then realise that if you actually ever use them in production code you better have a really good reason, or your colleagues will forever curse your name..

I think the above is probably the first time I've seen trigraphs used in the last 20 years or so.

[adito]

http://en.wikipedia.org/wiki/Digraphs_and_trigraphs#C

sorry for spoiling:

"??/" got replaced by "\"