Storing templated objects in a vector (Storing Class, Class in a single vector)

Question

There is a templated class, let it be

template class A { std::vector data; };

The problem I am facing here is,

Answer 1

std::any is the modern c++17 solution. Specifically, you should use

A a;
a.data.push_back(0);

// fill refernces...
std::vector refernces; 
refernces.push_back(&a.data[0]);

// check which type is active.
if(int** iPtr = std::any_cast(&references[0]); iPtr != nullptr)
{
     // its an int*
     int& i = **iPtr;
     // do something with i.
}

These pointers can point into the A::data and A::data vectors.

For a complete reference, see here https://en.cppreference.com/w/cpp/utility/any.