C? ?? ???: ?? ??? ??

C ??????? ?? ?? ??? ??? ???? ???? ?? ??? ? ????. ??? ??? ??? ?? ??? ???? ???? ???? ??????? ?? ?? ??? ????? ??? ?????.

??

?? ?? ???? ??? ??:

<code class="cpp">class AbstractComputation {
public:
    template <class T> virtual void setData(std::string id, T data) = 0;
    template <class T> virtual T getData(std::string id) = 0;
};

class Computation : public AbstractComputation {
public:
    template <class T> void setData(std::string id, T data);
    template <class T> T getData(std::string id, T data);
};</code>

???? ??? setData("foodouble", data)? ???? foodouble? ??? double? data ??? ???? ????.

??? ???

1. ?? ??? ??:

? ?? ?? ??? ?? ???(???)? ???? ?-? ?? ?? ?? ???? ???? ????.

<code class="cpp">class ValueStore {
    template <typename T>
    void setData(std::string const & id, T value);
    template <typename T>
    T getData(std::string const & id) const;
};

class AbstractComputation {
public:
    template <typename T>
    void setData(std::string const & id, T value) { m_store.setData(id, value); }
    template <typename T>
    T getData(std::string const & id) const { return m_store.getData<T>(id); }
protected:
    ValueStore m_store;
};</code>

? ???? ??? ???? ?????.

2. ?? ??? ??:

? ?? ??? ??? ???? ????? ?? ???? ???? ????.

<code class="cpp">class AbstractComputation {
public:
    template <typename T>
    void setData( std::string const & id, T value ) { setDataImpl( id, boost::any( value ) ); }
    template <typename T>
    T getData( std::string const & id ) const {
        boost::any res = getDataImpl( id );
        return boost::any_cast<T>( res );
    }
protected:
    virtual void setDataImpl( std::string const & id, boost::any const & value ) = 0;
    virtual boost::any getDataImpl( std::string const & id ) const = 0;
};</code>

??? Boost::any? ???? ?? ??? ???? ?????? ????? ???????. ?? ???? ????? ??? ?????.

? ??? C?? ?? ??? ??? ???? ??? ??? ?? ????? ?????? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!