g++ warn when double/float is converted to unsigned integer without using -Wconversion [duplicate]

Question

Possible Duplicate:
g++ -Wall not warning about double-> int cast

Per the question here, direct conversion from double/float to unsigned integer is not portable. I found I had a few cases in my code where this happens and I would like to tell g++ to warn me if this occurs, but I can't find such an option. Does anyone know if there is an option to do this?

Note: I do see -Wconversion, but that also warns about all kinds of other conversions that I don't care about (like converting int to unsigned int, which is portable per the standard).

Edit: Here's a code example for which I would like to see a warning:

double dblNumber = -234;
unsigned long uintNumber = dblNumber;

On one version of g++, this gives me an integer value of 0xFFFFFF16 (which is -234 in 2's complement) . On another it gives me 0. Clearly the code is ambiguous, which is why it is understandably not considered portable.

Answer 1

I know you said you don't want to use -Wconversion but it warns on the problem you care about, and at least in g++ 4.5 doesn't warn when converting long to unsigned long (for example). For any other cases that it warns where you're performing a legal desired conversion, just cast it. Your future maintainers will thank you greatly for making it explicitly clear that a known conversion is being done rather than guessing whether it's intentional or not from the code context.