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From: Brian McNamara (lorgon_at_[hidden])
Date: 2004-04-29 15:15:38

On Thu, Apr 29, 2004 at 10:05:19PM +0300, Justinas V.D. wrote:
> The problem is that lambda expressions do not have result_type defined
> although technically they are functors too (like STL functors). It would
> be trivial to write little metafunction wrapper though. After all,
> boost::lambda::is_lambda_functor metafunction exists but I haven't found
> lambda_result_type traits or something like that. Documentation
> conveniently skips through that part of implementation and code is a bit
> obscure at times.
> Is there a way to implement such a metafunction
> boost::lambda::functor_result<T>::type that it would return result
> type of lambda expression if T is lambda
> expression or T::result_type if T is ordinary STL functor, or just
> null_type if neither of them?
> that its implementation would not turn out to be a pain in the... emm...
> neck? Or perhaps this could be a part of Boost.Lambda library?

I think what you want is result_of.

Last I heard, a complete implementation had not yet made it into Boost.
Douglas? I think maybe Boost.Lambda already has the implementation
support for it, we just need the main result_of interface.

To Douglas: I am starting to have a little free time again, so if you
want help implementing it or making some tests, I will help here.

-Brian McNamara (lorgon_at_[hidden])

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