#include <cstddef>
#include <utility>

template<class T>
class UniquePtr  {
private:
    T *ptr = nullptr;

public:
    UniquePtr () {}
    UniquePtr (T * const _ptr) : ptr(_ptr) {  }
    UniquePtr (UniquePtr  &&_ptr) {
        ptr = _ptr.ptr;
        _ptr.ptr = nullptr;
    }

    UniquePtr& operator=(nullptr_t) {
        delete ptr;
        ptr = nullptr;
        return *this;
    }

    UniquePtr& operator=(UniquePtr &&_ptr) {
        delete ptr;
        ptr = _ptr.ptr;
        _ptr.ptr = nullptr;
        return *this;
    }
    ~UniquePtr () {
        delete ptr;
    }
    T& operator*() const {
        return *ptr;
    }
    T* operator->() const {
        return ptr;
    }
    T* release() {
        auto ans = ptr;
        ptr = nullptr;
        return ans;
    }
    void reset(T *_ptr) {
        delete release();
        ptr = _ptr;
    }
    void swap(UniquePtr &_ptr) {
        std :: swap(ptr, _ptr.ptr);
    }
    T* get() const {
        return ptr;
    }
    explicit operator bool() const {
        return ptr;
    }
};