C / C++ / MFC

((a).*(m))();

(a.*(m))();

Richard Andrew x64 wrote:

Excellent answer, as usual

class A{
	public:	void run(void);
};

class R{
public:	

	typedef void (A::*Method)();
	Method onClick;	

	void Do(A* a)	
	{		
		(a->*onClick) ();	
	}
};

int _tmain(int argc, _TCHAR* argv[])
{	
	printf("main\n");		
	A a;	
	R r;	
	r.onClick = &A::run;
	r.Do(&a);...
}

C c;<br />
c.method();

class T
{
public:
	virtual void run() = 0; // this does not have to be abstract if you don't like, but it saves some bits
	virtual void run1() = 0; // another possible event 
};

class A : public T
{
	public:	
		void run(){ // A version
		};

		void run1(){ // A version
		};
};

class F : public T
{
	public:	
		void run(){ // F version
		};

		void run1(){ // F version
		};
};

class R{
	public:	

	typedef void (T::*Method)(); // general abstract method used, it can point to any method without parameters
	Method onClick;	

	void Do(T* t) // abstract type used
	{		
		(t->*onClick)();	
	}
};

int _tmain(int argc, _TCHAR* argv[])
{
	A a;	// create object A
	F f;	// create object F

	R r;	
	r.onClick = &T::run; // set one general event

	// now different type passed leads to different call
	r.Do(&a); // A::run called
	r.Do(&f); // F::run called

	r.onClick = &T::run1; // set another general event

	// again different type passed leads to different call
	r.Do(&a); // A::run1 called
	r.Do(&f); // F::run1 called

	...

Ric Ashton wrote:

I'm assuming your running a few thousand records.

struct TestStruct
{
    CObject*   pObj;
 TestStruct()
 {
   pObj = new CObject[20];
 }
};

struct TestStruct{    
CObject   obj[ 20 ];
};

// everything is on the stack
{
TestStruct ts; // TestStruct constructor and 20 CObject constructors called

} // TestStruct destructor and 20 CObject destructors called
// nothing to delete, no memory leak

{
// everything is on the heap, ts and with that 20 CObject's
TestStruct *ts = new TestStruct; // TestStruct constructor and 20 CObject constructors called

// everything is destroyed 20 CObjects's and ts
delete ts; // TestStruct destructor and 20 CObject destructors called
}

{
// everything is on the heap, ts and with that 20 CObject's
TestStruct *ts = new TestStruct;

// no delete
}
// memory leak