[Object] Switch over to shared_ptr based implementation

[ShikiOkasaka]

cf. http://www.boost.org/doc/libs/1_54_0/libs/smart_ptr/sp_techniques.html#pimpl cf. http://channel9.msdn.com/Shows/Going+Deep/C-and-Beyond-2011-Scott-Andrei-and-Herb-Ask-Us-Anything [04:34]

The Object class could be something simple like,

class Object
{
protected:
    std::shared_ptr<Impl> pimpl;
public:
    constexpr Object() = default;
    constexpr Object(std::nullptr_t) {}
    explicit Object(Imp* pimpl) : pimpl(pimpl) {}
    Object(const std::shared_ptr<Imp>& pimpl) : pimpl(pimpl) {}
    ~Object() = default;

    std::shared_ptr<Impl> self() const {
        return pimpl;
    }

    Any message_(uint32_t selector, const char* id, int argc, Any* argv);
};

and the implementation class can be like,

class Impl : public std::enable_shared_from_this<Impl>
{
public:
    virtual Any message_(uint32_t selector, const char* id, int argc, Any* argv);
    std::shared_ptr<Impl> self() {
        return shared_from_this();
    }
};

The required changes to esidl would be relatively minor. In the escudo code base, we'll need to do surgery.

With this changes, we can create a new instance like,

 Node node(std::make_shared<NodeImpl>());

and we can also use weak_ptr where needed.

[ShikiOkasaka]

This switch is going to be of about 4,000 lines of changes in escudo. We will increment the minor version by one, and it will be 0.4.

[ShikiOkasaka]

esidl is updated at https://github.com/esrille/esidl/commit/acb6b125c330b757e53594dfad259c6954b90319.

[ShikiOkasaka]

Done at 0c895cbe1d325d33a5e5b6d16a1bfc6f8b480bd7.