In C++17, we can use variants.
To use std::variant, you need to include the header:
#include <variant>
After that, you may add std::variant in your code like this:
using Type = std::variant<Animal, Person>;
template <class T>
void foo(Type type) {
if (std::is_same_v<type, Animal>) {
// Do stuff...
} else {
// Do stuff...
}
}