on_exit Handler

ExitHandler.cpp

#include "ExitHandler.hpp"

#include <cstdlib>
#include <vector>


namespace ExitHandler {
namespace {
std::vector<AtExitFunctor> Functors;

void
AtExitHandler()
{
  for (const auto& functor: Functors) {
    functor();
  }
}
} // ns

bool
RegisterAtExit(AtExitFunctor functor)
{
  Functors.emplace_back(functor);
  // upon registering the first functor, register the atexit handler
  if (1 == Functors.size()) {
    return std::atexit(AtExitHandler) == 0;
  } else {
    return true;
  }
}
} // ns ExitHandler


#if EXAMPLE_USAGE
#include <iostream>
void
testFunction(int k) {
  std::cerr << "k = " << k << std::endl;
}

int
main(void)
{
  ExitHandler::RegisterAtExit(testFunction, 3);
  ExitHandler::RegisterAtExit(testFunction, 4);
}
#endif // EXAMPLE_USAGE

ExitHandler.hpp

////////////////////////////////////////////////////////////////////////////////
// License: Free as in 'bird'.
// A set of functions for C++ which mimic the non-portable `on_exit` function
// with a C++11 twist.
//
// This is especially necessary when signal handlers are out of your control and
// you need to clean up some resources.
//
// Usage:
//  void
//  someArbitraryFunction(std::string* pointerToDelete)
//  {
//    delete pointerToDelete;
//  }
//
//  int
//  main(void)
//  {
//    auto s = new std::string("Words!");
//    ExitHandler::RegisterAtExit(someArbitraryFunction, s);
//  }
////////////////////////////////////////////////////////////////////////////////

#ifndef EXIT_HANDLER_HPP_
#define EXIT_HANDLER_HPP_

#include <functional>

namespace ExitHandler {
using AtExitFunctor = std::function<void(void)>;

bool
RegisterAtExit(AtExitFunctor functor);

template <typename... _Args>
bool
RegisterAtExit(void(*functor)(_Args...),
               _Args&&... args)
{
  return RegisterAtExit(std::bind(functor, std::forward<_Args...>(args...)));
}

template <typename... _Args>
bool
RegisterAtExit(std::function<void(_Args...)> functor,
               _Args&&... args)
{
  return RegisterAtExit(std::bind(functor, std::forward<_Args...>(args...)));
}
} // ns ExitHandler

#endif // EXIT_HANDLER_HPP_