RAII - auto-cleanup based on object lifetime

raii.cpp

#include <iostream>
#include "raii.h"

int main() {
  int value = 0;
  std::cout << value << std::endl;
  
  // scope_guard c'tor arg is run on scope_guard destruction
  raii::scope_guard g( 
    [&](){
      value = 0;
      std::cout << value << std::endl;
  } );
  
  value = 6;
  std::cout << value << std::endl;
}

raii.h

#include <functional>

namespace raii {
  struct scope_guard {
    scope_guard(const std::function<void()>& f) : _f(f) {}
    ~scope_guard() { if (_f) _f(); }
  protected:
    std::function<void()> _f;
  };
}