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[C++] Overriding template class function

Started by Florian22222 Dec 22, 2011 at 9:15 AM 1 replies 450+ views

Original Post

Dec 22, 2011 at 9:15 AM

Hello!
I have a template class:


 template<class TYPE>
 class Dynamic
 {
 public:
 Dynamic(){ Create(); };
 virtual void Create() = 0;
 };
 
 class Triangle : public Dynamic<int>
 {
 public:
 virtual void Create()
 {
 //do something
 };
 };

if i compile this, i get an linker error for create().
if i use


 virtual void Create(){}; //in dynamic

instead, the create from dynamic is called and not from triangle.

Please help me, i cant cope with that.

wqking

Dec 22, 2011 at 9:23 AM

Don't use virtual function in constructor.
If you do use, the function is not polymorphism, it's one defined in current class.
If you really need to call virtual function, use named constructor idiom.


 class MyClass {
 public:
 static MyClass * newMyClass() {
 MyClass * instance = new MyClass;
 instance->someVirtualFunction();
 return instance;
 }
 };

Florian22222

Dec 22, 2011 at 9:42 AM

thank you!
I now made an extra method Create()

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