object.h

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#if !defined(__OBJECT_H)
#define __OBJECT_H

#include <atomic>
#include "constructor_stats.h"

class Object {
public:
    Object() { print_default_created(this); }

    Object(const Object &) : m_refCount(0) { print_copy_created(this); }

    int getRefCount() const { return m_refCount; };

    void incRef() const { ++m_refCount; }

    void decRef(bool dealloc = true) const {
        --m_refCount;
        if (m_refCount == 0 && dealloc)
            delete this;
        else if (m_refCount < 0)
            throw std::runtime_error("Internal error: reference count < 0!");
    }

    virtual std::string toString() const = 0;
protected:
    virtual ~Object() { print_destroyed(this); }
private:
    mutable std::atomic<int> m_refCount { 0 };
};

// Tag class used to track constructions of ref objects.  When we track constructors, below, we
// track and print out the actual class (e.g. ref<MyObject>), and *also* add a fake tracker for
// ref_tag.  This lets us check that the total number of ref<Anything> constructors/destructors is
// correct without having to check each individual ref<Whatever> type individually.
class ref_tag {};

template <typename T> class ref {
public:
    ref() : m_ptr(nullptr) { print_default_created(this); track_default_created((ref_tag*) this); }

    ref(T *ptr) : m_ptr(ptr) {
        if (m_ptr) ((Object *) m_ptr)->incRef();

        print_created(this, "from pointer", m_ptr); track_created((ref_tag*) this, "from pointer");

    }

    ref(const ref &r) : m_ptr(r.m_ptr) {
        if (m_ptr)
            ((Object *) m_ptr)->incRef();

        print_copy_created(this, "with pointer", m_ptr); track_copy_created((ref_tag*) this);
    }

    ref(ref &&r) : m_ptr(r.m_ptr) {
        r.m_ptr = nullptr;

        print_move_created(this, "with pointer", m_ptr); track_move_created((ref_tag*) this);
    }

    ~ref() {
        if (m_ptr)
            ((Object *) m_ptr)->decRef();

        print_destroyed(this); track_destroyed((ref_tag*) this);
    }

    ref& operator=(ref&& r) {
        print_move_assigned(this, "pointer", r.m_ptr); track_move_assigned((ref_tag*) this);

        if (*this == r)
            return *this;
        if (m_ptr)
            ((Object *) m_ptr)->decRef();
        m_ptr = r.m_ptr;
        r.m_ptr = nullptr;
        return *this;
    }

    ref& operator=(const ref& r) {
        print_copy_assigned(this, "pointer", r.m_ptr); track_copy_assigned((ref_tag*) this);

        if (m_ptr == r.m_ptr)
            return *this;
        if (m_ptr)
            ((Object *) m_ptr)->decRef();
        m_ptr = r.m_ptr;
        if (m_ptr)
            ((Object *) m_ptr)->incRef();
        return *this;
    }

    ref& operator=(T *ptr) {
        print_values(this, "assigned pointer"); track_values((ref_tag*) this, "assigned pointer");

        if (m_ptr == ptr)
            return *this;
        if (m_ptr)
            ((Object *) m_ptr)->decRef();
        m_ptr = ptr;
        if (m_ptr)
            ((Object *) m_ptr)->incRef();
        return *this;
    }

    bool operator==(const ref &r) const { return m_ptr == r.m_ptr; }

    bool operator!=(const ref &r) const { return m_ptr != r.m_ptr; }

    bool operator==(const T* ptr) const { return m_ptr == ptr; }

    bool operator!=(const T* ptr) const { return m_ptr != ptr; }

    T* operator->() { return m_ptr; }

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

    T& operator*() { return *m_ptr; }

    const T& operator*() const { return *m_ptr; }

    operator T* () { return m_ptr; }

    T* get_ptr() { return m_ptr; }

    const T* get_ptr() const { return m_ptr; }
private:
    T *m_ptr;
};

#endif /* __OBJECT_H */