Re: [Boost-users] [MPL] mpl::at for AssociativeSequence

12 Jun 2012


      On Tue, Jun 12, 2012 at 10:39 AM, Jeffrey Lee Hellrung, Jr. <
jeffrey.hellrung@gmail.com> wrote:
...
On Tue, Jun 12, 2012 at 9:11 AM,  wrote:
...
Hi list,
I'm trying to use the version of mpl::at with three template parameters,
as specified here (
http://www.boost.org/doc/libs/1_46_0/libs/mpl/doc/refmanual/at.html)
But I'm getting a compiler error saying 'boost::mpl::at' : too many
template arguments.
What am I doing wrong?
#include 
#include 
#include 
#include 
#include 
using namespace boost;
using namespace boost::mpl;
typedef map<
      pair
    , pair
    , pair,char[17]>
    , pair
    > m;
BOOST_MPL_ASSERT_RELATION( size<m>::value, ==, 4 );
BOOST_MPL_ASSERT_NOT(( empty<m> ));
BOOST_MPL_ASSERT(( is_same< at::type, unsigned > ));
BOOST_MPL_ASSERT(( is_same< at >::type, char[17] > ));
BOOST_MPL_ASSERT(( is_same< at::type, bool > ));
BOOST_MPL_ASSERT(( is_same< at::type, void_ > ));
BOOST_MPL_ASSERT(( is_same< at::type, void_ > )); // fails!
It seems there is a discrepancy between the documentation and the code; if
you take a look at boost/mpl/at_fwd.hpp, it forward declares boost::mpl::at
with only 2 template parameters :(
Please file a trac ticket, and I'll try to find out what the correct
resolution is on the developer's list.
- Jeff
Argh, sorry dariomt, Gordon has found this already in the trac database :/
My trac searching skills are evidently pretty poor :(

- Jeff