Failed to sort range

[Ali Çehreli]

On 05/28/2013 11:31 AM, Ali Çehreli wrote:

 >      @property Array!T opSlice(size_t i, size_t j) {
 >          // ...
 >          ret.front_ = i;
 >
 > I feel like the initialization of front_ above is not right either.
 > Imagine quick sort where we are slicing the right-hand side of a range
 > as [0..10], which has already been sliced before. Setting front_ to 0
 > would be wrong because then opIndex would still be counting from the
 > beginning of the original elements.

My explanation is wrong but I think there is still a bug. Imagine we are 
in the right-hand range that has been sliced as [10..$]. Now front_ is 
10 and all is good: s[0] provides the arr[10] of the original array.

Now imagine our slice again by [5..$]. s_further[0] should provide 
arr[15] of the original array but your setting front_ to 5 would 
unfortunately provide arr[5].

Ali