How do I call ::std::make_shared on a class with only protected or private constructors?

Question

I have this code that doesn\'t work, but I think the intent is clear:

testmakeshared.cpp

#include 

class A {
 public:
   stat         


        

Answer 1

#include 
#include 

class A : public std::enable_shared_from_this
{
private:
    A(){}
    explicit A(int a):m_a(a){}
public:
    template 
    static std::shared_ptr create(Args &&... args)
    {
        class make_shared_enabler : public A
        {
        public:
            make_shared_enabler(Args &&... args):A(std::forward(args)...){}
        };
        return std::make_shared(std::forward(args)...);
    }

    int val() const
    {
        return m_a;
    }
private:
    int m_a=0;
};

int main(int, char **)
{
    std::shared_ptr a0=A::create();
    std::shared_ptr a1=A::create(10);
    std::cout << a0->val() << " " << a1->val() << std::endl;
    return 0;
}