On 1/11/06, yinglcs2@yahoo.com <yinglcs2@yahoo.com> wrote:

Hi,

I have a non-growable, size determined by run-time array. For example convert this from Java to C: int[] func(int size) [ int[] array = new int[size];

return array; }

I was told the only way I can do that is using STL vector. But if I need to have a smart pointer for this STL vector, should I use the c++ auto_ptr? or the Boost's shared_ptr with STL vector or Boost's shared_array?

Thank you.

You could use any of these - there are advantages and disadvantages.... std::auto_ptr - no dependency on Boost - but the assignment semantics can be confusing at first - personally, I'd not use this. So, this leaves boost::shared_array and std::vector. std::vector is (IMO) the easier to use. However, when you return a std::vector from a function, it (including it's storage) will be copied. When you return a boost::shared_array, you effectively only copy the pointer, not the storage. This makes boost::shared_array slightly more time&space efficient IF you call this function a lot. (Note: if your compiler has return value optimisation, returning a std::vector may not incur a vector copy - but I wouldn't bank on having it) Personally, I would tend to use vector, because of the extra facilities it provides - specifically, it carries its size around with it, rather than me having to manage it! Stuart Dootson