派生类的Push_back shared_ptr

Question

I cannot understand what is going on with my code: why I get a "no matching function for call to push_back" error. I can only guess it is a newby mistake...

int main(){
  typedef std::tr1::shared_ptr<Base> Base_p;
  typedef std::vector<Base_p> VectorPointers_t;

  std::tr1::shared_ptr<Derived> myDer01(Derived); 
  VectorPointers_t myVector = VectorPointers_t();
  myVector.push_back(myDer01);  
}

Answer 1

Try this:

VectorPointers_t myVector;

myVector.push_back(Base_p(new Derived));

---

There is a big error in your code: The line declaring myDer01 actually declares a function and not aa variable. But even if you had written (Derived()) instead of Derived it would have been wrong, since you cannot construct a shared pointer from an object — only from a pointer! So you really want to say new Derived .

Answer 2

shared_ptr is a class template and each invocation of that template with different parameters will result in a separate class. The solution is to create only shared pointers to the base class.