Best practice for std::auto_ptr

Question

I'm just getting used to smart pointers using std::auto_ptr.

Assume that I want to call a function with both auto_ptr and normal Pointers.

auto_ptr<uint32> data_smart(new uint32[123])]);
uint32 data_fix[123];
uint32* data_dumb = new uint32[123];

processData(data_smart);
processData(data_fix);
processData(data_dumb);

What is the best practice for this without overloading? Having the processData function with a uint32* argument? Can I cast the smart pointer to uint32* for this case with .get()? Or what is the way I should do it? Thanks in advance!

Answer 1

1.

auto_ptr<uint32> data_smart(new uint32[123])]);

Don't do that. auto_ptr works with scalars only (it calls delete rather than delete[]).

2. auto_ptr owns the object it points to, so unless you want to pass the ownership to that function (in your code you don't), the function should accept a normal pointer. So you should change the call to:

processData(data_smart.get());

in order to explicitly express that data_smart continues to own the object.

Answer 2

EDIT: Noah Roberts' comment on your question is the bigger issue here, but this answers the question asked even if the example code is wrong....

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... without overloading ...

If you want to do it without overloading, the only option that's going to work for all of these is to make the method take a dumb pointer parameter.

Can I cast the smart pointer to uint32* for this case?

No. Use std::auto_ptr<t>::get().