C / C++ / MFC

CPallini wrote:

Only keenness keeps people focused and on task

CPallini wrote:

Only keenness kneenness keeps people focused

infectedprof wrote:

run in a powershell/terminal kind of environment.

class CValue
{
};

class CStringValue : public CValue
{
public:
    // CStringValue specific methods like void SetValue(const std::string&) and
    // const std::string& GetValue();
private:
    std::string m_Value;
};

class CIntValue : public CValue
{
public:
    // CIntValue specific methods like void SetValue(int) and
    // int GetValue();
private:
    int m_Value;
};

void SetValue(CValue* val);
CValue* GetValue();

class CStringValue;
class CIntValue;

class CValue
{
public:
    enum EType
    {
        EType_String,
        EType_Int,
    };
    virtual Etype GetType() = 0;

    // Downcast methods, not the most beautiful OO solution of the world but sometimes
    // in a fixed size class hierarchy like this it is acceptable and comfortable, and
    // more beautiful than using for example C++'s dynamic_cast. If quite comfortable
    // to say for example "if (CStringValue* sv = val->AsStringValue())"

    // override this only in CStringValue and put "return this;" into the method body.
    virtual CStringValue* AsStringValue() { return NULL; }
    // override this only in CIntValue and put "return this;" into the method body.
    virtual CIntValue* AsIntValue() { return NULL; }
};

class CValue
{
public:
    virtual std::string ToString() const = 0;
    virtual bool SetFromString(const std::string& s) = 0;

    // OK, lets support XML too...
    virtual void SaveToXml(XmlElement* node) = 0;
    virtual bool LoadFromXml(XmlElement* node) = 0;

    // TODO: put here your other useful utility virtual methods
};

class CValueVisitor;
class CValue
{
public:
    virtual void accept(CValueVisitor* visitor);
};

class CValueVisitor
{
public:
    virtual void visit(CStringValue* v) = 0;
    virtual void visit(CIntValue* v) = 0;
};