how do I tell an array pointer from a regular pointer-CodePudding

I'm writing a smart pointer like std::shared_ptr since my compiler does not support c 17 and later versions, and I want to support array pointer like:

myptr<char []>(new char[10]);

well, it went actually well, until I got the same problem as old-version std::shared_ptr got:

myptr<char []>(new char);

yeah, it can't tell whether it's a regular pointer or an array pointer, and since my deleter is kind of like:

deleter = [](T *p) {delete[] p;}

which means it just meets the same problem that the old-version std::shared_ptr has.

my array-pointer partial specialization is like:

template <typename T, typename DeleterType>
class myptr<T[], DeleterType> { // DeleterType has a default param in main specialization
                                // as std::function<void(T*)>
private:
    my_ptr_cnt<T, DeleterType> *p; // this is the actual pointer and count maintain class
public:
    // constructor
    /// \bug here:
    my_ptr(T *p, DeleterType deleter=[](T *p) {delete []p;}) :
        p(new my_ptr_cnt<T, DeleterType>(p, deleter)) { }

}

CodePudding user response：

You can't. This is one of the many reasons that raw arrays are bad.

What you can do is forbid construction from raw pointer, and rely on make_shared-like construction.