Re: [boost] [signals] is assertion necessary when no slots connected

From: Douglas Gregor (gregod_at_[hidden])
Date: 2004-02-17 18:45:19

On Tuesday 17 February 2004 05:01 pm, Jody Hagins wrote:
> asserts (if the default combiner is used).  I guess that makes sense,
> because there can be no "combined" return value if there are no slots.
> However, an assertion seems a bit harsh.  I am really not sure what
> should happen, but maybe an exception is a better alternative,

Well, we could throw bad_function_call, perhaps, or pick/create some other 
exception (I'm at a loss for exception names for this).

> or maybe 
> an alternative interface can define a default value to be returned if
> there are no slots connected), or maybe something else...

Well, you can always write a different combiner that does this.

> Anyway, I guess I was wanting to know why this is the case, and what is
> the usual method of handling this circumstance.  I assume something
> like:
>
>     if (!sig.empty())
>     {
>       result = sig();
>     }
>
> but that just does not look pretty...

No, it isn't pretty; perhaps the exception is the right way to go, depending 
on your application.

        Doug