Re: [Boost-users] multi-inheritance from elements of mpl::vector?==> inherit_scattered ( for Barton & Nackmann trick)

From: Oliver.Kowalke_at_[hidden]
Date: 2005-10-27 08:36:12

>>no reply - so I found a solution by myself (used for the Barton &
>> Nackmann trick)!
>> template< typename D >
>> struct F
>> {
>> 	std::string f()
>> 	{ return static_cast< D & >( * this).str_; }
>> };
>>
>> template< typename D >
>> struct G
>> {
>> 	std::string g()
>> 	{ return static_cast< D & >( * this).str_; }
>> };
>
>That's not the B&N trick; it's simple CRTP.
>The B&N trick is the one where you stick a friend function that
>applies to the derived class in the base class.  See the operators
>library for reference.

Sorry - in your book (C++ Template Metaprogramming, page 205) I can
read:
"The technique of using a static_cast with CRTP to reach the derived
object is sometimes called the "Barton and Nackmann trick" ...".
Is this wrong?

So long,
Oliver