creating a temporary fifo (tmpfile but for fifo)

[Timothee Cour via Digitalmars-d]

* std.stdio.tempfile creates an (unnamed) File. How do I create a temporary
fifo instead?
my workaround is to use tempnam but docs says it's not recommended (
http://man7.org/linux/man-pages/man3/tempnam.3.html)

* could we allow specifying a directory name for tmpfile?