C++ 20 - lezione 10

#include <iostream>
#include <concepts>
#include <format>

using namespace std;

template <typename T>
concept Number = integral<T> || floating_point<T>;

template <typename T1, typename T2>
concept Number2 = integral<T1> && floating_point<T2>;

template <typename T1, typename T2>
requires Number2<T1, T2>
T1 somma2(T1 a, T2 b) {
    return a + b;
}

template <typename T>
T somma(T a, T b) requires Number<T> {
    return a + b;
}

struct Punto3D {
    int x = 0;
    int y = 0;
    int z = 0;
};

struct Punto2D {
    int x = 0;
    int y = 0;

    Punto2D operator +(Punto3D &altro) const
    {
        return Punto2D{x+altro.x, y+altro.y};
    }
};


//forma abbreviata
auto somma3(Number auto n1, Number auto n2)
{ return n1+n2; }

template <Number T>
class UsaConcept {
public: UsaConcept(T numero) : valore{ numero } {}
    T valore;
};


template <typename T,typename T2>
concept isGuerriero =
requires(T guerriero, T2 coefficiente) {
    integral<T2>;
    {guerriero.attacca(coefficiente)} -> floating_point;
    guerriero.para();
};

template<typename G, typename C>
requires isGuerriero<G, C>
class Plotone{
    G soldati[100];
};

class Centurione
{
public:
    double attacca(int coefficiente) { return 4.5; }
    void para() {}
};

class Legionario {
public:
    void attacca() {}
    void para() {}
};

int main()
{
    //OK Centurione soddisfa il concept
    Plotone<Centurione, int> plot1 = Plotone<Centurione, int>();

    //Plotone<Legionario> plot2 = Plotone<Legionario>();


    Punto2D p1 { 5, 10 };
    Punto3D p2{ 4, -9, 12 };

    /*auto p3 = somma2<Punto2D, Punto3D>(p1, p2);
    cout << format("Punto risultato: ({},{})\n", p3.x, p3.y);*/

    cout << somma<int>(5, 3) << endl;
    cout << somma<double>(3.15, 56) << endl;


    //cout << somma2<int>(5, 3) << endl;
    //cout << somma2<double>(3.15, 56) << endl;
    //cout << somma2<double>(56, 3.15) << endl;
    cout << somma2(56, 3.15) << endl;
    cout << somma2<int>(56, 3.15) << endl;
    cout << somma2<int, double>(56, 3.15) << endl;

  //cout << somma<string>("ciao", " a tutti") << endl;



}