Getting a safe path for a temporary file

[via Digitalmars-d-learn]

Is it currently possible to get the path to a safe temporary 
file, i.e. one that is guaranteed to be freshly created and will 
not override another existing file?

There's `std.file.tempDir`, which doesn't create a unique file. 
Then there's `std.stdio.tmpfile()`, which does, but it returns a 
`File` object, and its `name` property is `null`.

Did I miss something? IMO this is very import functionality. One 
use case is passing these names as command line arguments to an 
external program that doesn't support stdin/stdout.