Re: g++ warning for unsafe operation

[mathieu]

Maxim Yegorushkin wrote:
> mathieu wrote:
>
> > Hi there,
> >
> >   I am looking for a warning in gcc that would warn me about
> > potentially dangerous operation, such as the one describe in (*). I
> > understand this is perfectly valid operation, but it looks to me like a
> > valid warning.
> >
> >   I tried the following so far:
> >
> > -Wall -Wextra -Wconversion -Wsign-compare
> >
> > Thanks
> > -Mathieu
> >
> > (*)
> > #include <vector>
> >
> > int main()
> > {
> >   std::vector<int> v;
> >   int s = 0;
> >   for(unsigned int i = 0; i < v.size() - 1; ++i) // v.size() == 0
> >     {
> >     s += v[i] * v[i+1];
> >     }
> >
> >   return 0;
> > }
>
> You could just change the loop to make it play well when 0 == v.size():
>
> for(unsigned int i = 1; i < v.size(); ++i)
> {
>     s += v[i - 1] * v[i];
> }

Not exactly what I was looking for, but the solution is very elegant.

Thanks !
-M