Re: [Boost-Users] boost::polymorphic_upcast suggestion

From: Darin Adler (darin_at_[hidden])
Date: 2002-06-27 09:11:01

On Thursday, June 27, 2002, at 06:38  AM, Jean Llorca wrote:

> Here upcasting means casting a base class to a derived class, I know 
> it may seem strange, bust boost offers a downcast
> which does the static_cast the language does implicitly already (check 
> <boost/cast.hpp>).

I think you've got it backwards. Downcasting, in Boost at least, means 
casting a pointer to a base class part of an object to a pointer to a 
derived class part of the same object. The polymorphic_downcast is 
*not* doing a static_cast for a conversion the language already does 
implicitly.

Could you give a specific complete example (a file that would compile, 
with all the declarations) of how one would use what you're proposing 
to help make this clearer?

     -- Darin