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;
}

Confirmed on Windows as well

C:\...\var> cl -Ic:\opt\include -EHsc var.cpp             
Microsoft (R) C/C++ Optimizing Compiler Version 18.00.31101 for x64   
Copyright (C) Microsoft Corporation.  All rights reserved.            
                                                                      
var.cpp                                                               
Microsoft (R) Incremental Linker Version 12.00.31101.0                
Copyright (C) Microsoft Corporation.  All rights reserved.            
                                                                      
/out:var.exe                                                          
var.obj                                                               
                                                                      
C:\...\var> var   
0         
22.5      
10        
22.5      
1000      
22.5      
100000    
22.5      
100000000 
22        
1000000000
-128

*** MUST NOT USE lazy***