Hello Rob, Without testing, I don't think your version will get things better. B/Rgds Max From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert Jones Sent: Thursday, January 22, 2009 6:20 AM To: boost-users@lists.boost.org Subject: Re: [Boost-users] Help with a boost::lambda problem and boost::array? On Wed, Jan 21, 2009 at 9:34 PM, <jesseperla@gmail.com> wrote: Does anyone have an idea why the following doesn't compile: using lambda::_1; using lambda::_2; boost::function<double (const boost::array<double, 2>&)> f = lambda::ret<double>(_1[0] * _1[1]); I'm not sure about this, but you might try boost::function<double (const boost::array<double, 2>&)> f = lambda::ret<double>( var(_1)[0]*var(_1)[1] ); Also, I don't know if you need the ret<double> bit. Cheers Rob.