coding-questions/problem/Smart pointer.cpp at master · checkcheckzz/coding-questions · GitHub

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/*
implement smart pointer in C++
*/

template <class T>
class SmartP {
public:
    SmartP(const SmartP<T>& p) { incRef(p); }
    SmartP(T* p) { assign(p); }
    ~SmartP() { decRef(); }


    SmartP<T>& operator = (const SmartP<T>& p) {
        if (this != &p)
        {
            decRef();
            incRef(p);
        }

        return *this;
    }

    T* operator ->() const { return val; }
    T& operator *() const  { return *val; }

private:
    void decRef() s{
        (*ref)--;

        if (0 == *ref)
        {
            delete val;
            delete ref;
        }
    }

    void incRef(const SmartP<T>& ptr) {
        ref = ptr.ref;
        val = ptr.val;
        (*ref)++;
    }

    void assign(T* p) {
        val = p;
        ref = new int(1);
    }

    T* val;
    int* ref;
};