PollableSourceFunc
typealias PollableSourceFunc = (<Error class: unknown class>, <Error class: unknown class>?) -> Boolean
This is the function type of the callback used for the #GSource returned by g_pollable_input_stream_create_source() and g_pollable_output_stream_create_source().
param
pollableStream
the #GPollableInputStream or #GPollableOutputStreamparam
data
data passed in by the user.return it should return false if the source should be removed.