When is using 'typeid' the best solution?

Question

There are many reasons not to use typeid. Other than for using members of type_info (implementation defined behavior), it is usually (always?) pos

Answer 1

Write a dynamic tree where you can on the runtime modify structure of the tree where there are different types in each link, it'll need typeid. dynamic_cast is not enough.

Edit: Here's some details:

class I {
public:
   virtual std::string type() const=0;
   virtual void *value() const=0;
};
template
class Impl : public I
{
public:
    Impl(T t) : t(t) { }
    std::string type() const { return typeid(T).name(); }
    void *value() const { return &t; }
private:
    T t;
};

And then build a tree out of these:

template
class Tree { };

With link type being the I* interface... Since the above works for any values of type T1,T2,T3,T4, we could also with similar classes for any functions T->T1, T->T2, T->T3, T->T4, and use that function type as the Node of the tree. Now you have proper expressions described in dynamic tree.