Re: [boost] generally replace *static_cast< T [const]* >(&x) -> static_cast< T [const]& >(x)?

Subject: Re: [boost] generally replace *static_cast< T [const]* >(&x) -> static_cast< T [const]& >(x)?
From: Arno Schödl (aschoedl_at_[hidden])
Date: 2011-05-27 13:02:41

> I believe casting through pointers is more restrictive and predictable than
> casting through references (e.g., T& could be even implicitly convertible to
> U& without T* convertible to U*; even the case of converting base_type& to
> derived_type& could be using some converting constructor in derived_type),
> so I don't think this would be a wise change indiscriminately.

> It looks to me like in this iterator_facade case, though, a reference cast
> is probably fine...

Of course, I missed that. Arguably, in all such cases, boost::addressof should be used because the result of an overloaded operator& is just as unpredictable as the result of a conversion operator.

So something like:

template< class T, class S >
T const& inheritance_cast( S const& s ) {
        return *static_cast< T const* >( boost::addressof(s) );
}

template< class T, class S >
T & inheritance_cast( S & s ) {
        return *static_cast< T * >( boost::addressof(s) );
}

Arno

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