Simple C++ program to demonstrate boost's variance accumulator

var.cpp

#include <iomanip>
#include <iostream>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/variance.hpp>
#include <boost/accumulators/statistics/stats.hpp>

namespace bacc = boost::accumulators;

static void
demo(const double base)
{
    bacc::accumulator_set<double, bacc::stats<bacc::tag::variance(bacc::lazy)> > acc;

    std::cout << std::setprecision(15) << base << '\n';

    acc(base + 4);
    acc(base + 7);
    acc(base + 13);
    acc(base + 16);

    std::cout << bacc::variance(acc) << '\n';

    return;
}


int
main(int argc, char *argv[])
{
    demo(0);
    demo(1e1);
    demo(1e3);
    demo(1e5);
    demo(1e8);
    demo(1e9);
    return 0;
}

*** MUST NOT USE lazy***