Unexpected failure-to-warn

[Tom St Denis]

Thomas Womack wrote:
>
> #include <iostream>
> using std::cout;
>
> int main(void)
> {
>   const int w = w/3;
> }
>
> does not give a 'warning, w may be used uninitialised', even when
> compiled with g++ -Wall, even though that's clearly the case.  I ran
> into this in real code - it's a common kind of thinko.
>
> Is this a bug, or am I missing something subtle in the C standard?

It does warn [gcc 4.1.2] if you up the optimization level.

Tom