David Abrahams wrote:

The extension docs show:

template <typename Iterator> typename result_of::deref<Iterator>::type deref(Iterator const& i) { typename result_of::deref<Iterator>::type result = extension::deref_impl<typename Iterator::ftag>:: template apply<Iterator>::call(i); return result; }

Isn't that more complicated than necessary and likely to inhibit RVO?

What about simply:

template <typename Iterator> typename result_of::deref<Iterator>::type deref(Iterator const& i) { return extension::deref_impl<typename Iterator::ftag>:: template apply<Iterator>::call(i); }

??

Yep. I'll let Dan deal with this (extension stuff). Anyway, I also noticed some non-RVO safe code in the library and fixed them. Thanks! Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net