title: Some questions about shared_ptr, scoped_ptr and shared_array
body: <p>I have some questions about smart pointers implemented in boost library.
  Is the only diffrence between shared_ptr and scoped_ptr that scoped_ptr doesn't have copy constructor and shared_ptr has it? 
  Should i use then scoped_ptr instead of shared_ptr always when object doesn't call copy constructor?
  I also doesn't understand idea of shared/scoped array. Can't I just use std::vector instead of it?</p>