#include <iostream> 

// here we have a bunch of structures to represent
// 3 dimensional math vectors, one with integer values
// and another with double precision floating point values
struct vec3i {
    int x;
    int y;
    int z;
};

struct vec3d {
    double x;
    double y;
    double z;
};

// and we define the dot product operation
int dot(vec3i v, vec3i w) {
    return v.x * w.x + v.y * w.y + v.z * w.z;
}

// notice that this function is also called dot() like the one above
// the difference is in the return value and the arguments
// this functions is said to *overload* the one before
double dot(vec3d v, vec3d w) {
    return v.x * w.x + v.y * w.y + v.z * w.z;
}


int main(int argc, char *argv[]) {

    vec3i a = { 1, 2, 3 };
    vec3i b = { 1, 2, 3 };
    // lets use our data and functions
    std::cout << dot(a, b) << std::endl;

    vec3d c = { .5, .2, 11.2 };
    vec3d d = { .2, .2, 12.3 };

    // notice how the compiler recognizes the type of the argument
    // and calls the correct dot() function
    std::cout << dot(c, d) << std::endl;

    return 0;
}