Expose `wait_readable` and `wait_writable` in SSLSocket

[ioquatix]

It seems like we don't expose this.

It was a problem for this PR: https://github.com/redis/redis-rb/pull/960

User should be able to expect to write:

io.wait_readable(timeout)
io.wait_writable(timeout)

But it doesn't seem to be working for SSLSocket.

It should be relatively trivial to implement, something like this:

        def wait_readable(timeout = nil)
          to_io.wait_readable(timeout)
        end

        def wait_writable(timeout = nil)
          to_io.wait_writable(timeout)
        end

Any thoughts?

[rhenium]

Agreed, that would be a nice addition. Other methods from io/wait (#nread - can simply return 0, #ready?, #wait, #wait_priority) can also be implemented in a similar way.

[djberg96]

Has this still not happened yet?