Access private constructor from public static member function using shared_ptr in C++

user_3554605 0
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Consider the following code where I'd like to delegate the creation of an A object to a method called make, in order to allow users of the class to only create instances wrapped in a std::shared_ptr:

#include <memory>

class A {
private:    
    A() {}

public:
    static std::shared_ptr<A> make() {
        return std::make_shared<A>();
    }
};

int main() {
    std::shared_ptr<A> a = A::make();
    return 0;
}

I would have thought that, because make is a member function, it would be allowed to access the private constructor, but apparently that's not the case. Compiling the program fails with the following message in the source of std::shared_ptr:

/usr/include/c++/8/ext/new_allocator.h:136:4: error: ‘A::A()’ is private within this context

How can I solve this issue?

shared-ptr class c++
1 Answers
class A {
private:
    A() {}

public:
    static std::shared_ptr<A> make() {
        return std::shared_ptr<A>(new A());
    }
};
user_29645970
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