Named Arguments C3 allows use of named arguments. Note that any unnamed arguments must appear before any named arguments and in the same order that they are declared. import std::io; fn void test(int x, double y) { io::printfn("%f", x + y); } fn void main() { test(x: 1, y: 3.0); test(3, 4.0); test(15, y: 3.141592); }