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#include<iostream>
class ComponentBase{
protected:
    static inline std::size_t component_type_count = 0;
};
template<typename T>
class Component : public ComponentBase{
public:
    // todo...
    // Change the current template class in any way so that for any type X, if it inherits from Component

    // Then X::component type id() will get a unique id of type size t (different values should be returned for different X types)值应不同）
    // Requirements: std::type info cannot be used (the typeid keyword is disabled), and all ids are consecutive starting from 0
};
class A : public Component<A>
{};
class B : public Component<B>
{};
class C : public Component<C>
{};
int main()
{
    std::cout << A::component_type_id() << std::endl;
    std::cout << B::component_type_id() << std::endl;
    std::cout << B::component_type_id() << std::endl;
    std::cout << A::component_type_id() << std::endl;
    std::cout << A::component_type_id() << std::endl;
    std::cout << C::component_type_id() << std::endl;
}