In this example why do I need CRTP?

问题

See Object counter example here: Why it just does not inherit from non-template class counter. Why counter should be template?

template <typename T>
struct counter

回答1:

Specializations will give you different counters for different types.
Note that those counters are static data members, thus shared among all instances of the given specialization.

来源：https://stackoverflow.com/questions/37530699/in-this-example-why-do-i-need-crtp