benchmark.hpp

#ifndef INCLUDE_BENCHMARK_HPP
#define INCLUDE_BENCHMARK_HPP
#include <chrono>
#include <cstdarg>
#include <cstdio>
#include <iostream>
struct __bench__ {
  typedef std::chrono::time_point<std::chrono::system_clock> time_type;
  time_type start;
  char msg[128];
  __bench__(const char* format, ...) __attribute__((format(printf, 2, 3))) {
    std::va_list args;
    va_start(args, format);
    std::vsnprintf(msg, sizeof(msg), format, args);
    va_end(args);

    start = get_time();
  }
  ~__bench__() {
    time_type end = get_time();
    std::fprintf(stderr, "%s: %6d ms\n", msg, diff_time(start, end));
  }
  time_type get_time(){
    return time_type::clock::now();
  }
  int diff_time(time_type a, time_type b){
    return std::chrono::duration_cast<std::chrono::milliseconds>(b-a).count();
  }
  operator bool(){
    return false;
  }
};
#define benchmark(...) if (__bench__ __b__ = __bench__(__VA_ARGS__)); else
#endif