On 3/1/2011 3:15 AM, Hossein Haeri wrote:
Hi Eric,
boost/proto/matches.hpp:391:13: error: invalid use of incomplete
type 'struct
boost::proto::detail::uncvrefarity_caller::CanBeCalledPlus2,
mpl_::integral_cint, 2 ::type' Now look at how you've defined
CanBeCalled:
templatetypename Fun, typename Int struct CanBeCalled;
Thanks. I added another specialisation for mpl::integral_cint, n
and it worked. But, now I'm wondering why on earth was that basically
needed? I had never touched mpl::integral_c in my code snippet. That
should have been generated by Proto then, right?
No.
And, in that case,
may I please know why?
Somewhere in your code you're adding two MPL integers. That's just how
MPL works. Your code is assuming a particular type of Integral Constant
(mpl::int_). MPL only promises to give you /a/ MPL Integral Constant.
On the other hand, I'm wondering why GCC never nagged about the need
for mpl::integral_cint, 1 when I wrote:
EW1InpPool, GameState, AmmoMsg() Plus1();
In other words, why is mpl::int_n used for the above line (when n
== 1), whereas mpl::integral_cint, n is used for the following one
(when n == 2)?
(EW1InpPool, GameState, AmmoMsg() || EW1InpPool, GameState,
AmmoMsg()) Plus2();
Probably because the former isn't doing an addition of MPL Integral
Constants.
This is an MPL gotcha. Others have complained about it on the boost
list, IIRC.
--
Eric Niebler
BoostPro Computing
http://www.boostpro.com
___
proto mailing list
proto@lists.boost.org
http://lists.boost.org/mailman/listinfo.cgi/proto
