D-Programming-Language/druntime — pull request #214 by alexrp (2012-05-13 01:09:03+00:00)
Title: Make thread attach/detach behavior less annoying to work with.

This just makes it so attaching an already-attached thread or detaching
an already-detached thread doesn't result in undefined behavior and/or
Bad Things (TM). Making the user do these checks is fairly pointless
because they almost always have to be done. We may as well do them
internally.