primitive value overflow

[Jonathan M Davis]

On Thursday, May 16, 2013 22:42:23 luka8088 wrote:
> I agree that it is exactly the same as checking if (text1.length >
> text2.length). And I don't think that this is an issues if you are aware
> of the fact that you are working with unsigned values. But in the code
> that I wrote there was no mentioning of unsigned so the possibility of
> that kind of issue never came to mind until I actually printed the
> values. And that is what I wanted to emphasize.

Well, I'm not sure what can be done about that. length is size_t, which is the 
unsigned integral value which matches the architecture (uint for 32-bit and 
ulong for 64-bit). AFAIK, the documentation is clear on this (though I haven't 
read it recently). If it's not, then it should be made clearer, but using 
size_t for length is pervasive in D as it is in C++, and if you know the 
standard types, you know what size_t is.

As for overflow checking, it's come up quite a few times, and Walter is 
completely against it. The hardware doesn't support it, and it would definitely 
be slow if it were added. The standard way to handle that if you want it is to 
create user-defined integral type which does the checks (though that obviously 
won't help you when you can't control the types that you're dealing with). But 
if you want to add checks in your code, you can always create a wrapper 
function for doing the subtraction. And if you wanted the checks to only be 
there in non-release mode, then you could even put the checks in a 
version(assert) block. So, you can add checks if you want them, but there's 
pretty much no way that how unsigned or overlflow are handled in the language 
is going to change.

- Jonathan M Davis