Question

I’ve had a hard time finding references in the TR1 documentation concerning shared arrays. The Boost documentation is fairly clear that there is a significant difference between the C++ ‘new’ and ‘new[]’ expressions. The shared_ptr template is meant to correctly hold a pointer to a dynamically allocated objected created using ‘new’. The shared_array template is meant to correctly hold a pointer to a dynamically allocated array using ‘new[]’.

I’m in the process of updating some code to use the TR1 shared_ptr template and associated functions, but I’ve found no mention of shared_array. Does the TR1 shared_ptr implementation differentiate between ‘new’ and ‘new[]’, and destroy those pointers correctly? As far as I can tell from looking at the TR1 spec, it appears it does not. If this is the case, should I still be using the boost shared_array template for ‘new[]’ style allocations?

Answer 1

That is correct, there is no shared_array in TR1.

You can, however, provide your own deleter object to perform ‘delete []’ if you wish using this constructor:

template<class Other, class D>    shared_ptr(Other* ptr, D dtor); 

For example:

template<typename T> struct my_array_deleter {    void operator()(T* p)    {       delete [] p;    } };  shared_ptr<int> sp(new int[100], my_array_deleter<int>());