Re: [Boost-users] [shared_ptr] Implicit cast shared_ptr<derived> to shared_ptr<base>

From: Alan M. Carroll (amc_at_[hidden])
Date: 2008-08-21 13:30:48

"shared_ptr<T> can be implicitly converted to
shared_ptr<U> whenever T* can be implicitly converted
to U*. In particular, shared_ptr<T> is implicitly
convertible to shared_ptr<T const>, to
shared_ptr<U> where U is an accessible base of
T, and to shared_ptr<void>. "

http://www.boost.org/doc/libs/1_36_0/libs/smart_ptr/shared_ptr.htm

At 07:47 AM 8/21/2008, you wrote:
> Hi there,
>
> after making what I then thought was a bad mistake, I discovered that
> the
> code below actually works (gcc 4.3.1, OpenSUSE 11 64bit, Boost 1.36).
> I.e.,
> there is an implicit cast from shared_ptr<derived> to
> shared_ptr<base> to
> make it fit the function argument, although both represent different
> types.
>
> Is this intended behaviour (i.e. portable) ? I did not find a
> corresponding
> description in the docu.