pretty benchmark class

bench.cpp

// the idea is to benchmark and output pretty results

#include <iostream>
#include <functional>
#include <chrono>
#include <vector>

struct Fun
{
  std::string name;
  std::function<void()> fun;

  Fun(std::string const &name, std::function<void()> fun)
  : name(name)
  , fun(fun)
  {}
};

struct Bm
{
  std::vector<Fun> funs;

  void bench(Fun const &fun)
  {
    funs.push_back(fun);
  }

  template<typename... Args>
  typename std::enable_if<std::is_constructible<Fun, Args...>::value>::type bench(Args&& ...args)
  {
    bench({std::forward<Args>(args)...});
  }

  std::chrono::milliseconds run(std::ostream &o= std::cout)
  {
    using namespace std::chrono;
    milliseconds total(0);
    for(auto &fun: funs)
    {
      o<< fun.name<< ": ";
      auto t= high_resolution_clock::now();
      fun.fun();
      auto d= duration_cast<milliseconds>(high_resolution_clock::now()- t);
      o<< d.count()<< "ms\n";
      total+= d;
    }
    o<< "total: "<< total.count()<< "ms\n";
    return total;
  }
};

int main()
{
  Bm bm;
  bm.bench("f1", [](){
    for(uint64_t i= 0; i< 100000000; ++ i);
  });
  bm.bench("f2", [](){
    for(uint64_t i= 100000000; i--;);
  });
  bm.run(std::cout);
}