Re: [Boost-users] [signals] thread-safe post-disconnect() cleanup

From: Frank Mori Hess (frank.hess_at_[hidden])
Date: 2007-02-23 17:52:00

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On Friday 23 February 2007 17:26 pm, Timmo Stange wrote:
> You can look at random_signal_system.cpp for a real example, but it's
> quite simple: A class can provide a predefined function class and
> an overload for visit_each. The connecting code creates an instance
> of that class to connect to the signal and doesn't need to care about
> tracking, because it is set up by the slot and visit_each.
>
> struct some_observer
> {
>    signals::tracked ptr_to_some_secret_object;
>    some_observer();     // Sets up ptr_to_some_secret_object
>    void operator()();   // Uses ptr_to_some_secret_object
> };
>
> ...
>
>    signal0<void> sig;
>    sig.connect(some_observer());
>
> The advantage is that the party establishing the connection does
> not need to know what objects have to be tracked. It's not such a
> big asset, but it's something you cannot do with the explicit
> track().

Ah, I see.  Couldn't you achieve the same thing by deriving some_observer 
from the slot class?  Then the some_observer constructor could call 
slot::track() to set up its own tracking.

- -- 
Frank
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