JuliaLang/julia — pull request #3871 by stevengj (2013-07-29 17:00:24+00:00)
Title: added isopen(io) for IOStream and IOBuffer

We already had `isopen` for some `AsyncStream` types. Pretty trivial implementation.

This function is useful for passing IO objects to Python (since Python's `IOBase` [interface](http://docs.python.org/3/library/io.html#io.IOBase)) includes an `isclosed` function.