std::vector<Base*> derivedVector;
.
.
.
derivedVector.push_back(new Derived1(someParameter);
derivedVector.push_back(new Derived2(someParameter);
derivedVector.push_back(new Derived3(someParameter);
//note: I delete all these dinamically allocated Deriveds in the destructor of this class

Original post by xissburg
A generalization of my problem: suppose I have a class Base(an abstract class) and some others Derived1, Derived2 and Derived3(not abstract) which are derived from Base. I also have in another class a std::vector<Base*> where I store Derived1, Derived2 and Derived3 objects[.quote]
Stop. You don't have a container of objects. You have a container of pointers to objects. It's a fundamental and extrememly important difference, and has been the cause of much misunderstanding. Make sure you understande the difference.

Quote:How would I search or sort this vector using a specific comparison function?? And if instead of a std::vector it was an array?! The basic qsort() and bsearch() doesn't work because the array pointer will be incremented wrongly.

The C standard library algorithms are inadequate for most C++ applications.

Use the C++ standard library algorithms. They're faster, easier, and better able to cope with the twenty-first century.

I would recommend using std::sort and supplying your own comparison predicate function. The simplest way to do that would be to have a member function of you Base class that provides the comparison and bind that using one of the std::mem_fun variants, but I could understand if you find those confusing and hard to read. In that case, create a namespace-level function that take two const Base* objects as parameters and returns bool true.

  bool BaseComparator(const Base* lhs, const Base* rhs)  {    return lhs->value() < rhs.value();  }  // ...  std::sort(derivedVector.begin(), derivedVector.end(), BaseComparator);

And hey presto! this exact same code will work for C-style arrays.

--smw

string GetInfo(){    char buf[512];    //think of GetWeight() as a pure virtual function which is defined at some derived class    //it does some specific computation for that kind of object and returns a float    //and GetNotes() is also a pure virtual function which returns a class specific string with some info    sprintf_s(buf, "Name: %s\nWeight: %.2f\nNotes: %s\n", name, GetWeight(), GetNotes().c_str());//I was getting some runtime errors with this    return string(buf); // !!! what about this ^^?!}//GetNotes() is something like thisstring GetNotes(){    return string("Some Thing");//hm?! =/}