Some code of my learning on C++

assignment1.cpp

#include <iostream>

using namespace std;

// Implicit type casting
float test_function(void) {
    uint16_t a = 30;
    float b = 10.4;
    return a + b; 
}

// Function overloading
int sum(int a, int b) {
    return a + b;
}

float sum(float a, float b) {
    return a + b;
}

char sum(char a, char b) {
    return a + b - '0';
}

// Default argument
float thrust_budget(uint8_t rotor_number = 4,
                    float max_thrust_per_rotor = 15.3,    // kg
                    float rotor_weight = 1.2,             // kg  
                    float drone_weight = 13,              // kg
                    float payload_weight = 12             // kg
                    ) {
    return (rotor_number * max_thrust_per_rotor) - (
            rotor_number * rotor_weight) - drone_weight - payload_weight;
}

// Check float equality
#define EPSILON    (1.0E-8)

bool is_equal(float a, float b) {
    //return (a == b)? true : false;
    float diff = a - b;
    return (diff < EPSILON) && (diff > -EPSILON);
}

// Pass by reference
void pass_by_value(int arg) {
    arg++;
}

void pass_by_reference(int &arg) {
    arg++;
}

void pass_by_pointer(int *arg) {
    (*arg)++;
}

class Takeme {
    private:
        int i;
    public:
        Takeme () {
            this->i = 0;
        };

        Takeme & operator ++ () {
            this->i++;
            return *this;
        }

        operator int () const {
            return this->i;
        }
};


// Main
int main() {
    cout << test_function() << endl;

    cout << sum(1, 2) << endl;
    cout << sum(1.1f, 2.2f) << endl;
    cout << sum('1', '2') << endl;

    cout << thrust_budget() << endl;
    cout << thrust_budget(6) << endl;
    cout << thrust_budget(8) << endl;
    cout << thrust_budget(12) << endl;

    cout << (char *[]){"false", "true"}[ is_equal(1.2f, 1.2f) ] << endl;
    cout << (char *[]){"false", "true"}[ is_equal(1.2f, 1.1f) ] << endl;

    int normal_v = 0;
    pass_by_value(normal_v);
    cout << normal_v << endl;
    pass_by_reference(normal_v);
    cout << normal_v << endl;
    pass_by_pointer(&normal_v);
    cout << normal_v << endl;

    Takeme takeme;
    cout << ++takeme << endl;

    return 0;
}