Do we have closures in C++?

Question

I was reading about closures on the net. I was wondering if C++ has a built-in facility for closures or if there is any way we can implement closures in C++?

Answer 1

Yes, This shows how you could implement a function with a state without using a functor.

#include 
#include 


std::function make_my_closure(int x){
    return [x]() mutable {   
        ++x;
        return x;   
    };
}

int main()
{
    auto my_f = make_my_closure(10);

    std::cout << my_f() << std::endl; // 11
    std::cout << my_f() << std::endl; // 12
    std::cout << my_f() << std::endl; // 13

     auto my_f1 = make_my_closure(1);

    std::cout << my_f1() << std::endl; // 2
    std::cout << my_f1() << std::endl; // 3
    std::cout << my_f1() << std::endl; // 4

    std::cout << my_f() << std::endl; // 14
}

I forgot the mutable keyword which introduced an undefined behaviour (clang version was returning a garbage value). As implemented, the closure works fine (on GCC and clang)