Fix ruby warning.
%extend tinyspline::Vec4 {std::string to_s() { return $self->toString(); }}
%rename("%(undercase)s", %$isfunction) "";
-%rename("%(undercase)s", %$ismember, %$not %$isconstructor) "";
+%rename("%(undercase)s", %$ismember, %$not %$isconstructor, %$not %$isenumitem) "";
// Map std::vector<tinyspline::real> to Ruby array.
%typemap(out) std::vector<tinyspline::real> * {
