// ### Functions
// a simple function
void functionName() {}

// function with parameters of integers
void functionName(int param1, int param2) {}

// return type declaration
int functionName() {
    return 420;
}

// Return multiple values at once
// (C++ uses pairs [ 2 values ] and tuple [ more than 2 values ])
// Please refer pairs and tuple respectively for more information
std::tuple<double, double> functionName() {
    return std::make_tuple( double1, double2 );
}

pair<double,double> result = functionName();
std::cout << result.first << std::endl;
std::cout << result.second << std::endl;

// Pass by reference (the caller and the callee use the same variable for the parameter)
int functionName(int &referenceName) {}

// Pass by value (the caller and callee have two independent variables with the same value)
int functionName(int valueName) {}