It should be as simple as using the "sample" keyword in the boost::accumulators namespace, like:

using namespace boost::accumulators; accumulator_set< int, featurestag::weighted_sum > acc( sample = 42 )

Thanks Eric. Indeed, it works ! But my problem was actually independent of this. I am using more features, and it seems that we can't use more than 4 tagged arguments !!! using namespace std; using namespace boost::accumulators; typedef accumulator_set, double> AccType1; typedef accumulator_set, double> AccType2; typedef accumulator_set, double> AccType3; double probs[] = {0.01,0.05, 0.25, 0.33, 0.5, 0.67, 0.75, 0.95, 0.99}; vector<double> q_probs(probs, probs + sizeof(probs) / sizeof(double)); AccType1 acc1(tag::weighted_density::cache_size = 10, tag::weighted_density::num_bins = 10, tag::weighted_extended_p_square::probabilities = q_probs, tag::weighted_p_square_cumulative_distribution::num_cells = 10); // compiles (4 tagged arguments) // AccType1 acc2(sample = 42, tag::weighted_density::cache_size = 10, // tag::weighted_density::num_bins = 10, // tag::weighted_extended_p_square::probabilities = q_probs, // tag::weighted_p_square_cumulative_distribution::num_cells = 10); // Error : does not compile (5 tagged arguments) AccType2 acc3(sample = 42, tag::weighted_density::cache_size = 10, tag::weighted_density::num_bins = 10, tag::weighted_p_square_cumulative_distribution::num_cells = 10); // compiles (4 tagged arguments) AccType3 acc4(sample = 42, tag::weighted_density::cache_size = 10, tag::weighted_density::num_bins = 10, tag::weighted_extended_p_square::probabilities = q_probs); // compiles (4 tagged arguments) I wanted acc2, so I thought my syntax using the "sample" keyword was wrong but it was not, as acc3 and acc4 do compile. Is that a bug ?

On 10/11/2010 8:05 AM, Adrien Todeschini wrote:

I am using more features, and it seems that we can't use more than 4 tagged arguments !!! <snip> Is that a bug ?

On 10/11/2010 9:39 AM, Eric Niebler wrote:

Sounds like it. Could you try defining BOOST_PARAMETER_MAX_ARITY to be something higher, like 10?

Done, but it does not solve the problem. The error message from GCC 4.4.3 compiler is : In file included from /usr/include/boost/accumulators/accumulators.hpp:12, from /sandbox.hpp:13, from ../BiipsTest.cpp:11: /usr/include/boost/accumulators/framework/accumulator_set.hpp: In constructor ‘boost::accumulators::accumulator_set::accumulator_set(const A0&, const A1&, const A2&, const A3&, const A4&) [with A0 = boost::parameter::aux::tagged_argument, A1 = boost::parameter::aux::tagged_argument, const int>, A2 = boost::parameter::aux::tagged_argument, const int>, A3 = boost::parameter::aux::tagged_argument, std::vector >, A4 = boost::parameter::aux::tagged_argument, const int>, Sample = int, Features = boost::accumulators::features, Weight = double]’: /sandbox.hpp:90: instantiated from here /usr/include/boost/accumulators/framework/accumulator_set.hpp:200: error: no match for call to ‘(boost::accumulators::detail::accumulator_params) (boost::accumulators::accumulator_set, double>&, const boost::parameter::aux::tagged_argument&, const boost::parameter::aux::tagged_argument, const int>&, const boost::parameter::aux::tagged_argument, const int>&, const boost::parameter::aux::tagged_argument, std::vector >&, const boost::parameter::aux::tagged_argument, const int>&)’ /usr/include/boost/parameter/parameters.hpp:841: note: candidates are: boost::parameter::aux::empty_arg_list boost::parameter::parameters::operator()() const [with PS0 = boost::parameter::required, PS1 = boost::parameter::optional, PS2 = boost::parameter::void_, PS3 = boost::parameter::void_, PS4 = boost::parameter::void_] Adrien

On 10/12/2010 0:37 PM, Eric Niebler wrote:

Bummer. Can you file a bug at http://svn.boost.org? I don't want this issue to get lost.

Done : svn.boost.org/trac/boost/ticket/4730 By the way, I did not mention that I am using Boost 1.40. Can someone try on the latest release ?