[boost] [shared_ptr] Design question about make_shared

Hello everybody, I recently wondered about the choice to make make_shared a free function, and not a static member function: struct A{...}; struct B:A {...}; shared_ptr<A> ptr = make_shared<B>(arg1,arg2); vs shared_ptr<A> ptr = shared_ptr<B>::make(arg1, arg2); I was wondering if this is just a stylistic choice, or if there are some differences? Thank you for any information. -- Loïc