c_g_output_stream_splice

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
__gshared extern (C)
ptrdiff_t function(GOutputStream* stream, GInputStream* source, GOutputStreamSpliceFlags flags, GCancellable* cancellable, GError** err) c_g_output_stream_splice;

Meta