/*
 * SPtr.hpp
 *
 *  Created on: Feb 25, 2016
 *      Author: mike
 */

#ifndef SPTR_HPP_
#define SPTR_HPP_

#include <iostream>
#include <exception>

#include "Serial.hpp"

using namespace std;
using T = double;

// ----------------------------------------------------------------------------
// Smart pointer exception class
class SPexception : std::exception {
private:
    string s;
public:
    SPexception( string s ) : s(s) {}
    virtual const char* what() const noexcept { return s.data(); }
};

// ----------------------------------------------------------------------------
// Smart pointer class
class SPtr {
private:
    Serial& uidGen = Serial::uidGen();    // assigns UID to each SPtr
    unsigned* count = 0;    // shared object among all SPtr with same target
    T* target = nullptr;    // shared target object
    const int my_id = uidGen();    // identifying label

public:
    // Default constructor
    SPtr();
    // Construct an SPtr to manage p
    SPtr(T* p);
    // Copy constructor
    SPtr(const SPtr& sp);
    // Copy assignment
    SPtr& operator=(const SPtr& sp);
    // Move constructor
    SPtr(SPtr&& sp);
    // Move assignment
    SPtr& operator=(SPtr&& sp);
    // Destructor
    ~SPtr() {
        cout << "  Destructor called for SPtr " << id() << endl;
        reset();
    }

    bool empty() const { return count==nullptr; };
    void reset();
    int id() const { return my_id; }

    // Follow operator.
    T& operator*() {
        if (!empty()) return *target;
        else throw SPexception("Can't follow empty SPtr");
    }
};

#endif /* SPTR_HPP_ */