I need to dynamically create instances of an Aggregate in C++ which inherits from multiple base classes, where the combination of base classes can vary based on runtime conditions. I want to avoid pre-populating all possible combinations.

Here’s a simplified version of what I’m trying to achieve

I have several base classes:

class CharBase
{
    CharBase() { std::cout << "CharBasen"; }
};

class UnsignedCharBase
{
    UnsignedCharBase() { std::cout << "UnsignedCharBasen"; }
};

class ShortBase
{
    ShortBase() { std::cout << "ShortBasen"; }
};

class IntBase
{
    IntBase() { std::cout << "IntBasen"; }
};

I use the following Aggregate class template to unherit from multiple base classes

template<typename... Bases>
class Aggregate : Bases…
{
    Aggregate() { std::cout << "Aggregaten"; }
};

My goal is to create instances of the Aggregate classes on demand based on runtime conditions. The expected result is to create an Aggregate instance as if I hardcoded it, for example:

new Aggregate<CharBase, UnsignedCharBase, ShortBase>
new Aggregate<UnsignedCharBase, IntBase>