Function sourceview5_sys::gtk_source_completion_provider_list_alternates

pub unsafe extern "C" fn gtk_source_completion_provider_list_alternates(
    self_: *mut GtkSourceCompletionProvider, 
    context: *mut GtkSourceCompletionContext, 
    proposal: *mut GtkSourceCompletionProposal
) -> *mut GPtrArray

This is supported on crate feature v5_0 only.