RE: [boost] [smart_ptr] const-correctness as function argument

From: scleary_at_[hidden]
Date: 2002-10-02 07:35:56

> -----Original Message-----
> From: Larry Evans [mailto:jcampbell3_at_[hidden]]
> 
> I haven't looked real close, but doesn't the subsection titled
> "Smart Pointers and const" in Item 28 of Scott Meyers
> _More Effective C++_ contain a solution to this problem?
> Basically, it describes SmartPtr<T>  derived from
> SmartPtrToConst<T> and SmartPtrToConst<T> containing
> a union of const and non-const pointers to T.  Unfortunately,
> this would require changing shared_ptr.

That item is concerned with allowing a conversion of smart_ptr<T> to
smart_ptr<const T>.  Scott does this by redefining SmartPtr<const T> to be
SmartPtrToConst<T>.  The Standard solves the same problem in auto_ptr by the
use of templated constructors/assignment.  Boost solves that problem in
shared_ptr in essentially the same way as the Standard.  That problem does
not exist with scoped_ptr, since copy construction/assignment do not exist.

        -Steve