On Sun, 7 Mar 2004, E. Gladyshev wrote:
I must have missed it in the docs. Is InputIterator is a random access iterator?
No, it's an input iterator.
Can I do *(first+2)? When do iterators become invalid?
Assume input iterator semantics, only.
For example can I store an InputIterator instance for later?
No.
How is InputIterator connected to groups?
Not at all :)
What is the order... is the 'last' iterator is the last connection?
Yes, but remember that the order is very loosely specified.
The doc says that the order of slot calls is unspecified, is it true for InputIterators?
Yes. The order of slot calls is unspecified within a group.
Is it possible to have stateful combiners?
Yes.
If so, how can I modify the combiner's state before generating a signal?
Hmmm, that's a problem.
For instance is it possible to do something like this:
struct call_slot { bool b; typedef bool result_type;
template<typename InputIterator> bool operator()(InputIterator first, InputIterator last) { if(b) do_something1( first, last ); else do_something2( first, last ); } };
Yes, but it seems that I've omitted any way to get to the combiner. Sounds like something we should add.
A related question is if I have an instance of
boost::signals::connection,
is it possible to get an access to the slot that this connection is referencing?
No.
Back when Signals was designed, there was no way to use this capability because boost::function objects were entirely opaque. Now they're a bit less opaque (in CVS, at least, because of operator==), so this could be seen as more of a hindrance.
Mybe there is another way to accomplish what I want? I'd like to have an efficient method for "capturing" signals, so that a slot can be temporarily designated as a sole signal destination.
typedef boost::signals::signal< void (int) > my_signal; struct client {...};
main { my_signal sig;
client c1, c2; boost::signals::connection con = sig.connect(c1); sig.connect(c2);
set_capture( s, c1 /*or should it be con?*/ );
sig(1); //the signal is sent to c1 only
remove_capture( s );
sig(1); //the signal is sent to all slots }
Is there a natural way to implement set_capture/remove_capture?
Not that I can think of.
In other words, was such a feature considered during the Signals design?
No, it wasn't. What sort of application do you need it for? It's interesting.
I am sorry for so many questions. If there are some references that I need to look at, I'd happy to do so.
Just the reference docs. Doug