🚀 go-pugleaf

solution@gate.net (Ken Walter) writes:

>I always thought the following was interesting:
>
>template <class T, class S> T cast_d( S s) { return dynamic_cast<T>s; }

That won't quite do what you want, because you are using
pass-by-value.  That will result in copying, giving `cast_d' quite
different semantics to `dynamic_cast'.  You should use
pass-by-reference instead.  You then need to overload the function to
allow all possible sorts of references:

template <class T, class S> T cast_d(S &s) 	 { return dynamic_cast<T>s; }
template <class T, class S> T cast_d(const S &s) { return dynamic_cast<T>s; }
template <class T, class S> T cast_d(volatile S &s)
						 { return dynamic_cast<T>s; }
template <class T, class S> T cast_d(const volatile S &s)
						 { return dynamic_cast<T>s; }

--
Fergus Henderson             	WWW: http://www.cs.mu.oz.au/~fjh
fjh@cs.mu.oz.au              	PGP: finger fjh@128.250.37.3
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