3.Containers::vector::type_trait

https://cplusplus.com/reference/vector/vector/?kw=vector

https://velog.io/@zhy2on/C-STL-SFINAE-enableif

is_integral

template<typename> struct is_integral_base: std::false_type {};

template<> struct is_integral_base<bool>: std::true_type {};
template<> struct is_integral_base<int>: std::true_type {};
template<> struct is_integral_base<short>: std::true_type {};

allocate 메모리 할당, construct 할당된 공간에 데이터 생성

...

https://velog.io/@zhy2on/C-STL-SFINAE-enableif