D-Programming-Language/phobos — pull request #2225 by tom-tan (2014-06-03 03:11:05+00:00)
Title: Make std.stdio.LockingTextWriter.put and lockingTextWriter @safe

We can mark `std.stdio.lockingTextWriter` as safe because the constructor of `LockingTextWriter` is safe.

`LockingTextWriter.put` for ranges uses `core.stdc.stdio.fwrite` but we can verify it can be trusted.
`LockingTextWriter.put` for char type uses `FPUTC` and `FPUTWC` but we can verify they can be trusted.
I define nested trusted functions for them.