A confusing expression?

[Andrej Mitrovic]

Maybe we should have a special DMD flag to enable alternate warnings.

Maybe call it.. -walter ?

;P

bearophile Wrote:

> Time ago an automatic tool has said that in a line of C code similar to:
> int r = x / y * z;
> 
> a division operator followed by a mult is confusing, and to add parentheses to improve the code:
> int r = (x / y) * z;
> 
> 
> When values are integral the position of parentheses can change the value of the expression:
> 
> void main() {
>     int x = 10;
>     int y = 3;
>     int z = 5;
>     assert(x / y * z == 15);
>     assert((x / y) * z == 15);
>     assert(x / (y * z) == 0);
> }
> 
> 
> Turning 'x / y * z' into a D syntax error (as done in bug  http://d.puremagic.com/issues/show_bug.cgi?id=4077 ) looks excessive to me. A warning seems enough, but Walter is not a lover of warnings (and sometimes I agree, I'd like to turn three D warnings into errors). What do you think?
> 
> Bye,
> bearophile