哪个 STL 容器适合存储数百万用户定义（类）数据？

Question

Suppose we've millions of custom data that need to be stored and search later these which STL will be good? let's say

class A{ 
    public:
      int i;
      float f;
      string s;
};

We need to to store the objects of class A.

Answer 1

Which STL Container will be good to store millions of user define(class) data?

All of them, except for std::array .

and search later

Depends on the kind of searching. The associative containers have efficient lookup operations.