"Ranges..." => "Needles..." in [starts|ends]With.
To avoid any confusion: The stuff in ranges may or may not actually be ranges. generic "Needles" is what best describes it.
Clean up endsWith unittests
Original author wrote "wrap" because filter is not bidirectional. However, the function filterBidirectional fits the need, so migrating to that.
Bit of unicode unittest in [starts|ends]With
Just sprinkling some tests. These covered a wee little bit of missing usecases.
Optimizations in startsWith
* Consolidate implementation by checking length in a single spot.
* Checks narrow string or the same types' lengths.
* Index iterates on all RA ranges (and not just Arrays).

Ends with was left untouched, because it forwards to startsWith anyways.
Optimization in startsWith(Range, Needles...)
Basically, makes it stop searching as soon as an element as matched.

This is an important optimization, that avoids a lot of startsWith's other "non-optimzations"...
Implement nextPermutation for bidirectional ranges.
Implement nextEvenPermutation.
Improve ddocs for nextPermutation and nextEvenPermutation.
Improve documentation.
Add unittests for non-default sorting order.
Fix rollover bug in nextEvenPermutation.
Add non-trivial example for nextEvenPermutation.
Oops, fix typo in ddoc.
support for non RA with length in startWith

As suggested by Andrei.

Also: More unittests
Prettify std.math. Cosmetic changes only.

Prettify brace placement, remove unused mfeq() unittest function.
Merge pull request #1106 from donc/stdmathprettify

Prettify std.math. Cosmetic changes only.
Fixes Issue 8920 - iota should work with types smaller than int.
Merge pull request #1035 from monarchdodra/startWith

Maintenance in [starts|ends]With
Merge pull request #1022 from quickfur/permute

Implement nextPermutation and nextEvenPermutation
Merge pull request #1107 from AndrejMitrovic/Fix8920

Issue 8920 - iota should work with types smaller than int