integer cast in object_.d

[Michel Fortin]

On 2011-09-05 02:57:33 +0000, Andrej Mitrovic 
<andrej.mitrovich at gmail.com> said:

> I'm looking at compare() in class TypeInfo_Array and it's defined as:
> 
> override int compare(in void* p1, in void* p2)
> {
>     void[] a1 = *cast(void[]*)p1;
>     void[] a2 = *cast(void[]*)p2;
>     size_t sz = value.tsize();
>     size_t len = a1.length;
> 
>     if (a2.length < len)
>         len = a2.length;
>     for (size_t u = 0; u < len; u++)
>     {
>         int result = value.compare(a1.ptr + u * sz, a2.ptr + u * sz);
>         if (result)
>             return result;
>     }
>     return cast(int)a1.length - cast(int)a2.length;
> }
> 
> Shouldn't that return line be:
> return cast(int)(a1.length - a2.length);
> 
> To make it 64-bit safe?

Per the rules of modular arithmetic substraction, both will give you 
the same result actually. And no it isn't 64-bit safe.


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/