id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
5302	[accumulator] Generalise type arithmetics, e.g. make it play well with boost.units.	alfredo.correa@…	Eric Niebler	"Accumulators library assumes that for an accumulated type T*T is also of type T. This makes it difficult to play it well with boost.unit for example; specially for the variance accumulator.

Based on http://groups.google.com/group/boostusers/msg/86ebe100e3a86794
Below is the goal code:

#include<boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/variance.hpp>
#include<boost/units/systems/si.hpp>
#include<boost/units/io.hpp>

using namespace boost::accumulators;
using namespace boost::units;
int main(){
	accumulator_set<
		quantity<si::time>, 
		features<
			tag::variance, 
		> 
	> a;
	a(1.0*si::second);
	a(2.0*si::second);
	a(3.0*si::second);
	std::cout 
		<< extract::variance(a)
	;
	return 0;
}
"	Bugs	new	To Be Determined	accumulator	Boost 1.45.0	Problem