当我需要多态时，如何避免动态分配？

Question

With GCC on Ubuntu 14.04 and the following MCVE:

class TargetInterface
{
public:
   ~TargetInterface();
   //
   DataBuffer retDataBuffer();
   // following methods are all pure virtual
   virtual void delay() = 0;
   // ...
protected:   
   DataBuffer dataBuffer;
}

class FlashTarget : public TargetInterface
{
   public:
   void delay() override;
   // ...
}   

// globals
TargetInterface * targetInterface;

void main()
{
    targetInterface = new FlashTarget; // <--
    // ...
    // etc.
}

FlashTarget is derived from TargetInterface and targetInterface is dynamically allocated in main() .

Is there a way to avoid dynamic allocation for the above code?

Answer 1

This would be the naive answer:

void main()
{
    FlashTarget target;
    targetInterface = ⌖
}

Note: with this approach, you must ensure that target will live as long as targetInterface is used.