0 < negative loop condition bug or misunderstanding on my part

[Timon Gehr]

On 03/08/2012 03:39 AM, Ary Manzana wrote:
> On 3/7/12 2:28 AM, Ali Çehreli wrote:
>> On 03/06/2012 09:11 PM, ixid wrote:
>> > I'm writing my first basic algorithms, this one is merge sort. This
>> > version throws an exception when array.length - setSize is negative
>> > (which should be fine, the rest of my function would deal with it):
>> >
>> > template mergeSort(T)
>> > {
>> > void mergeSort(ref T[] array, const T setSize = 100)
>> > {
>> > T[][] merge;
>> > merge.length = array.length / setSize;
>> > T ii, jj;
>> > for(ii = 0, jj = 0;ii < array.length - setSize;ii += setSize, ++jj)
>>
>> We don't know what T is, but I assume a signed type like int.
>>
>> array.length is size_t, i.e. an unsigned type. Unsigned types have this
>> nasty habit of converting the entire expression to unsigned (that is a
>> rule since C). So array.length - setSize above is size_t.
>
> Wouldn't it make more sense to convert the entire expression to signed
> if there's at list one signed integer?
>

This is just as arbitrary as the rule that says the entire expression is 
converted to unsigned.