the type of the value that this expression evaluates to
marshaller used for creating a closure
expressions for each parameter
callback used for creating a closure
user data used for creating a closure
destroy notify for @user_data
a new GtkExpression
ConstructionException GTK+ fails to create the object.
This function is a variant of [ctor@Gtk.ClosureExpression.new] that creates a GClosure by calling g_cclosure_new() with the given callback_func, user_data and user_destroy.