#include struct vec2 { double X, Y; }; void print(struct vec2 S, struct vec2 T) { printf("%f, %f, %f, %f\n", S.X, S.Y, T.X, T.Y); } int main() { struct vec2 U, V; U.X = .5; U.Y = 1.2; V.X = -123.01; V.Y = 1/3.0; print(U, V); return 0; }