How to use 'make_ptr()' while T is a class with private construction?

Question

I was working with singleton pattern and shared_ptr.I was trying to make the code like this:

class A{
    private:
        static std::shared_ptr<A> instance;
        A();
    public:
        static std::shared_ptr<A> creatInstance();
};

std::shared_ptr<A> A::creatInstance(){
    if(!instance){
        instance=std::make_shared<A>();
    }
    return instance;
}

But I got a compiler error. Any thoughts? I tried to make make_shared be a friend function of class A,but it didn't work.

friend shared_ptr<A> make_shared<A>();

score 0 · Answer 1 · edited May 23 '17 at 12:14

0

It seems that std::make_shared< A > requires public constructor of A.

Here is a few solutions of this problem - How do I call ::std::make_shared on a class with only protected or private constructors?

edited May 23 '17 at 12:14

Community

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1

answered Jul 01 '15 at 10:05

Robert Wadowski

1,407
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thanks a lot,it really help. – Jul 02 '15 at 01:48

How to use 'make_ptr()' while T is a class with private construction?

1 Answers1