On 4/11/2010 9:37 AM, Daniel Walker wrote:
On Sat, Apr 10, 2010 at 7:50 PM, Eric Niebler <eric@boostpro.com> wrote:
If Boost.TR1 advertises itself as an implementation of TR1, then it should have an implementation of result_of that doesn't rely on decltype. (Waiting for John to jump in here.) That way, libraries like Proto that need the tr1 behavior (until decltype is fixed) can use std::tr1::result_of from boost/tr1/functional.hpp and forget about it. This should be possible in the 1.44 time frame and is a good long-term solution.
Agreed.
Note that to make this happen, you'll need to coordinate with John. The way Boost.TR1 works is like this: - If the platform implements <tr1/foo_header>, include it. Otherwise, - Include <boost/foo_header.hpp> and bring boost::foo into the std::tr1 namespace with a using declaration. If boost::result_of sometimes uses decltype, the above won't work because then std::tr1::result_of will sometimes use decltype. It seems to me that <boost/utility/result_of.hpp> should expose a boost::tr1_result_of that can be used by <boost/tr1/result_of.hpp> to get the TR1 behavior regardless of whether decltype exists or not. -- Eric Niebler BoostPro Computing http://www.boostpro.com