Smart pointers in container like std::vector?

Question

I am learning about smart pointers (std::auto_ptr) and just read here and here that smart pointers (std::auto_ptr) should not be put in containers

Answer 1

theoretically you can use std::auto_ptr with STL containers if you completely understand their internal implementation and don't do anything that can lose auto_ptr ownership, but practically it's much more safe to use containers with raw ptrs.

"In reality, how often does this happen?" - is very dangerous question by itself. first of all, STL - it's not a single standard implementation, there're many. Each one can implement containers in different ways, so your highly tuned code to avoid all "auto_ptr in containers" mines can burst switching to another STL implementation. Also, your code maintenance will be highly complicated, any correctly looking change to your code can break your program. how can you remember that or force others maintainers to remember? putting warnings in any place where such changes can occur? impossible.

so, conclusion: it's just a bad idea that brings nothing but headache