D-Programming-Language/phobos — pull request #1665 by monarchdodra (2013-10-25 20:01:09+00:00)
Title: Fix Issue 11356 - isASCII for strings

http://d.puremagic.com/issues/show_bug.cgi?id=11356

As mentioned in the boards. Having this is useful to warrant inclusion, and the (non-trivial) implementation is substantially faster than the obvious one.