G'day all.

In retrospect I shouldn't have brought up a "more powerful"
call_once function, because that's not what I want at all.  What
I "really" want is this:

	class once
	{
	public:
		once();
		~once();
		call_once(function0<void> &);
	};

On Tue, Aug 06, 2002 at 09:13:26AM -0400, Pete Becker wrote:

>  The one place where they seem useful is in lazy initialization. But rather 
>  than thinking in C terms and prolonging the life of the inside-out 
>  interface to once functions, think C++ and design a more suitable solution:
>  
>  class lazy_initializer
>  {
>  public:
>          lazy_initializer();
>          ~lazy_initializer();
>          void init_once();
>  private:
>          virtual void do_init() = 0;
>  };

This is in fact exactly what I wanted to use the once operation for,
except that my class needs more than one piece of data which is lazily
evaluated.  Admittedly composing with more than one lazy_initializer
class would work, but it seems less clean than just dropping a few once
objects into the class.

Cheers,
Andrew Bromage
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