With the new standard coming (and parts already available in some compilers), the new type std::unique_ptr
is supposed to be a replacement for std::auto_ptr
.
Does their usage exactly overlap (so I can do a global find/replace on my code (not that I would do this, but if I did)) or should I be aware of some differences that are not apparent from reading the documentation?
Also if it is a direct replacement, why give it a new name rather than just improve the std::auto_ptr
?
You cannot do a global find/replace because you can copy an auto_ptr
(with known consequences), but a unique_ptr
can only be moved. Anything that looks like
std::auto_ptr<int> p(new int);
std::auto_ptr<int> p2 = p;
will have to become at least like this
std::unique_ptr<int> p(new int);
std::unique_ptr<int> p2 = std::move(p);
As for other differences, unique_ptr
can handle arrays correctly (it will call delete[]
, while auto_ptr
will attempt to call delete
.