Re: [Boost-users] boost.proto optimization on MSVC (2005/2008)

"Eric Niebler" wrote in message news:475AEB69.9070304@boost-consulting.com...

I'm confused. So your vector2<> type is intended as a wrapper for any kind of terminal, not arrays?

vector2<> doesn't wrap terminals, it just wraps regular types to provide uniform access to them with a vector (math vector) interface. This way vector2, vector2, and vector2<D3DXVECTOR> could all be used with expressions regardless of their underlying type, and additional types can be used just by specializing vector2<T> and providing the subscript operator as well as some traits.

So how is your example different than any of the examples in proto's docs?

I based it off of the lazyvector example, but the code does not optimize as expected. (In fact, all I really did was swap out the vector type.)

Have you tried using proto::extends<> (or BOOST_PROTO_EXTENDS) to extend terminal<T>::type instead of terminal::type ? You'll also need to patch up your grammar to accept any kind of terminal.

I'm not sure that's the correct approach... proto should not have to know about the internal type of vector2<> at all. I could do this with a helper type where vector2 extends vector2_internal which contains all the functionality, but then I'm faced with the problem that the many specializations of vector2_internal<> could have different constructors which would no longer be accessible through the vector2 interface.