Pbar

A tiny header-only progress bar library for C++. The progress bar is itself an iterator, whose operator++() is overloaded to output a progress bar to std::clog on each call.

Usage

#include <iostream>
#include <vector>
#include <unistd.h>
#include "pbar.h"

using namespace pbar;

int main() {
  int us = 100000;
  std::vector<int> v = {1, 2, 3, 4, 5};
  // Construct a ProgressBar for iterating over v, with a total width of 50 characters
  ProgressBar<std::vector<int>::iterator> pbar(v.begin(), v.end(), 50);
  for (auto i = pbar.begin(); i != pbar.end(); i++) {
    usleep(us);
  }

  // In C++17, the template argument may be omitted
  // The constructor allows changing the bar symbol (default '=')
  ProgressBar pbar2(v.begin(), v.end(), 50, '#');

  std::cout << "\nRange based loops also work" << std::endl;

  for (auto& i: pbar2) {
    usleep(us);
  }
}

Notes

Currently, calling ProgressBar::begin() resets the internal counter to zero, so calling begin() on the progress bar object during iteration will reset the bar. This is not ideal, so for the moment you shouldn't call begin() on the ProgressBar when you need to access the first element, but instead call it on the actual container you're iterating over.

Credits

• This StackOverflow answer, where I got part of the implementation from.
• Toby Speight on codereview stackexchange, who helped signicantly improve the code quality.