_ref_count.h

Go to the documentation of this file.

/* === S T A R T =========================================================== */

#ifndef __ETL__REF_COUNT_H
#define __ETL__REF_COUNT_H

/* === H E A D E R S ======================================================= */

#include "_curve_func.h"
#include <cassert>

/* === M A C R O S ========================================================= */

/* === T Y P E D E F S ===================================================== */

/* === C L A S S E S & S T R U C T S ======================================= */

_ETL_BEGIN_NAMESPACE

class weak_reference_counter;

// ========================================================================
class reference_counter
{
    friend class weak_reference_counter;
private:
    int* counter_;
public:

    reference_counter(const bool &x=true):counter_(x?new int(1):0) { }

    reference_counter(const reference_counter &x):counter_(x.counter_)
        { if(counter_) (*counter_)++; }

    reference_counter(const weak_reference_counter &x);

    ~reference_counter() { detach(); }

    reference_counter& operator=(const reference_counter &rhs)
    {
        detach();
        counter_=rhs.counter_;
        if(counter_)
        {
            assert(*counter_>0);
            (*counter_)++;
        }
        return *this;
    }

    void detach()
    {
        if(counter_)
        {
            assert(*counter_>0);
            if(!--(*counter_))
                delete counter_;
            counter_=0;
        }
    }

    void reset()
    {
        detach();
        counter_=new int(1);
    }

    int count()const { return counter_?*counter_:0; }

    bool unique()const { return counter_?*counter_==1:0; }

    operator int()const { return count(); }
}; // END of class reference_counter

// ========================================================================
class weak_reference_counter
{
    friend class reference_counter;
private:
    int* counter_;
public:
    weak_reference_counter():counter_(0) { }

    weak_reference_counter(const weak_reference_counter &x):counter_(x.counter_) { }

    weak_reference_counter(const reference_counter &x):counter_(x.counter_) { }

    ~weak_reference_counter() { }

    weak_reference_counter& operator=(const reference_counter &rhs)
    {
        counter_=rhs.counter_;
        assert(*counter_>0);
        return *this;
    }

    weak_reference_counter& operator=(const weak_reference_counter &rhs)
    {
        counter_=rhs.counter_;
        assert(*counter_>0);
        return *this;
    }

    void detach() { counter_=0; }

    int count()const { return counter_?*counter_:0; }

    bool unique()const { return counter_?*counter_==1:0; }

    operator int()const { return count(); }
}; // END of class weak_reference_counter

inline reference_counter::reference_counter(const weak_reference_counter &x):
    counter_(x.counter_)
{
    if(counter_) (*counter_)++;
}

_ETL_END_NAMESPACE

/* === E X T E R N S ======================================================= */

/* === E N D =============================================================== */

#endif