Add Radix Sort

[nordlow]

I have a radix sort implementation at

https://github.com/nordlow/justd/blob/master/intsort.d#L92intsort.d

which beats Phobos own Quicksort by a factor 1.5 to 4 depending on element type (Intergral or FloatingPoint).

Run the unittest and see for yourself.

Not that I've made it work for floating point too using the functions at

https://github.com/nordlow/justd/blob/master/intsort.d#L58

that realizes bijections between

• uint32 <=> float
• uint64 <=> double

Nobody (including me) has had the time to get it into Phobos.

If you feel like you can included it here aswell.

The two most important todos are:

• Figure out a way to template-parameterize radixSortImpl to make it work on aggregate element types when the comparison function can be expressed as an data-member-accessor of the aggregate. For example if ElementType is a struct S { int x, y; } and comparison function "a.x < b.x".
• If possible implement a generic sorting algorithm that automatically selects the best suitable in-Place sorting algorithm based on types of the input parameters (range and comparsion/accessor function). This currently means isIntegral, float, double, and as above mentioned aggregates sorted on a member or combination of members whose bijection can fit into 8, 16, 32 or 64 bits.

[Xinok]

I appreciate it but I'd like to keep the code in this repository as my own. Otherwise, since I don't have my own implementation of radix sort, I could provide a link to your code in the README so others can find it. I know the README is huge; I've been meaning to move the module descriptions into separate files which would give your link greater prominence.

Also, sorry for the late response. I haven't given any attention to this repository lately as it's been on the back burner for some time.

[Xinok]

I've pushed a draft of a new README and provided a link to your radix sort code. I'll replace the old README once I'm done restructuring this repository.