mkstemp

[Stephen Weeks]

I propose adding the following to MLton's basis.  Comments?

val MLton.TextIO.mkstemp: string -> string * TextIO.outstream

Here is the implementation (within the context of the basis library
implementation).

      val mkstemp = _ffi "mkstemp": char array -> int;

      val mkstemp: string -> string * outstream =
	 fn s =>
	 let
	    val s = String.concat [s, "XXXXXX\000"]
	    val n = String.size s
	    val a = Array.tabulate (n, fn i => String.sub (s, i))
	    val fd = mkstemp a
	    val _ = PosixError.checkResult fd
	    val name = String.tabulate (n - 1, fn i => Array.sub (a, i))
	 in
	    (name, newOut (PosixPrimitive.FD fd))
	 end