Re: [boost] Re: about function.hpp

From: Rainer Deyke (root_at_[hidden])
Date: 2001-05-07 22:57:57

----- Original Message -----
From: "Jesse Jones" <jesjones_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Monday, May 07, 2001 4:55 PM
Subject: [boost] Re: about function.hpp

> Sure, you return a cookie used to identify the timer. But if you make
> the reasonable requirement that   you can't install multiple timers
> on one callback you can ditch the cookie. I don't think it buys you
> anything: it's just one more piece of data for users to juggle.
> Whereas with my approach you can create a new callback whenever you
> need to interact with the timer.

In the specific case of timers, you probably want a class to manage the
lifetime of a timer:

class Timer {
  Timer(const function<void>& g, int ms) : f(g) { whatever.add_timer(f,
ms); }
  ~Timer() { whatever.remove_timer(f); }
private:
  boost::function<void> f;
};

Without such a class, your code is either not exception safe, or exceedingly
difficult to read/maintain, or both.  Given the necessity of such a class,
it doesn't really matter if the underlying mechanism uses cookies or not.

--
Rainer Deyke (root_at_[hidden])
Shareware computer games           -           http://rainerdeyke.com
"In ihren Reihen zu stehen heisst unter Feinden zu kaempfen" - Abigor