Re: [boost] [Smart Ptr][Bind] Implementaion of Weak Callback Function

Subject: Re: [boost] [Smart Ptr][Bind] Implementaion of Weak Callback Function
From: Artyom (artyomtnk_at_[hidden])
Date: 2009-03-22 06:06:36

>   weak_ptr< A > p;
> 
>   bind(&A::foo, throw_if_invalid(p));
>   bind(&A::foo, ignore_if_invalid(p));
>   bind(&A::foo, call_if_invalid(p, bar)); // bar

I think this is little bit problematic, because proxy
weak_ptr_caller should know the signature of A::foo
to provide correct "R operator()(args...)"

Maybe, additional policy for weak_fn would be better

void A::foo(int);
function<void(int)> bar;

bind(weak_fn(&A::foo,p),_1); // default ignore
bind(weak_fn(&A::foo,p,throw_on_invalid()),_1);
bind(weak_fn(&A::foo,p,bar),_1); // call bar on invalid

This would not require changes in bind and also
weak_fn would be useful without bind as well.

Like function<void(int)> foobar=weak_fn(&A::foo,p);
It would be simple to update weak_fn to add policy


Artyom