auto_ptr

[mce]

Hi,

I have a few questions regarding this auto_ptr

1) I should only use auto_ptr within a function??

2) Can i use auto_ptr<int> or auto_ptr<SomeClass> in a class?
example:

class Test
{
private:
auto_ptr<int> ptrData;
}

If not why?

3)auto_ptr<std::vector> vec1 for example, why is it after copying such as
auto_ptr<std::vecotr> vec2(vec1), vec2 becomes unmodifiable? how to get around this?

[laserlight]

3)auto_ptr<std::vector> vec1 for example, why is it after copying such as
auto_ptr<std::vecotr> vec2(vec1), vec2 becomes unmodifiable? how to get around this?

You probably mean to say that vec1 no longer owns the vector. Basically, auto_ptr has unusual copy semantics...

2) Can i use auto_ptr<int> or auto_ptr<SomeClass> in a class?

... so if you have an auto_ptr member in a class, and you don't disable copying, you'll have to worry about the unusual copy semantics that objects of your class will have...

1) I should only use auto_ptr within a function??

... hence using an auto_ptr in the way you would use Boost's scoped_ptr is a way to keep things simple.

Note that the 2011 version of the C++ standard introduces std::unique_ptr and deprecates std::auto_ptr (because of the problems that it can cause, and the fact that unique_ptr can replace it for what it is useful for).