Re: [boost] Smart pointers and array types

From: Howard Hinnant (hinnant_at_[hidden])
Date: 2001-01-07 15:05:46

Peter Dimov wrote on 1/7/2001 2:46 PM
>No, this is not what I had in mind. The code checks whether it's dealing
>with the array version. Whether it's called auto_ptr<X[]> or auto_array<X>
>makes no difference.

To form the new expression (single or array) is going to be an issue no 
matter what the smart pointer's name is.  The checking is done prior to 
the construction of the smart pointer in order to form the new 
expression.  After the construction of the smart pointer, the code is 
ignorant of the type of smart pointer (in both examples).  (and in the 
T[] example, the code is ignorant of the type of smart pointer at the 
construction site).

Perhaps my examples should have moved the new expression out of foo and 
into main to be more clear:

template <class T>
void
foo(typename remove_bounds<T>::type* p, std::size_t n)
{
        auto_ptr<T> ap(p);
        for (int i = 0; i < n; ++i, ++p)
                do_it(*p);  // might throw
}

int main()
{
        foo<int>(new int, 1);
        foo<int[]>(new int[3], 3);
}

-Howard