try_convert

Try to convert obj into an IO, using to_io method. Returns converted IO or nil if obj cannot be converted for any reason.

IO.try_convert(STDOUT)     # => STDOUT
IO.try_convert("STDOUT")   # => nil

require 'zlib'
f = open("/tmp/zz.gz")       # => #<File:/tmp/zz.gz>
z = Zlib::GzipReader.open(f) # => #<Zlib::GzipReader:0x81d8744>
IO.try_convert(z)            # => #<File:/tmp/zz.gz>