std::regular

#include <concepts>
#include <iostream>

template<std::regular T>
struct Single {
    T value;
    friend bool operator==(const Single&, const Single&) = default;
};

int main()
{
    Single<int> myInt1{4};
    Single<int> myInt2;
    myInt2 = myInt1;

    if (myInt1 == myInt2)
        std::cout << "\n";

    std::cout << myInt1.value << ' ' << myInt2.value << '\n';
}