Re: callback design question
On Mar 1, 12:17 pm, "dasjotre" <dasjo...@googlemail.com> wrote:
On 1 Mar, 07:19, "mliptak" <Meht...@gmail.com> wrote:
I have been using libsigc/signals for several years
and I warmly recommend it.
So I gave it a try and instead of using virtual functions I used the
But I gained nothing in terms of performance and also the interface
remained pretty much the same.
So what's the rationale behind using signals / slots?
signals/slots is a very simple library.
you have much less restrictive interface with signals than with
virtual void fun1(A &)=0;
virtual void fun2(B &)=0;
with this approach you have to implement both functions even if
you don't use one of them
You can do the default implementation in the base class as well,
instead of pure virtuals..
signal<void (A&)> asignal;
signal<void (B&)> bsignal;
slots are arbitrary function objects
you can connect any function object that is convertible to
asignal.connect(bind(&T:fun, &t, _1));
you can bind extra arguments and adapt
interface to fit the signal.
void my_fun(A & a, int n);
asignal.connect(bind(&my_fun, _1, 4));
you have much more robust
and functional connection management.
void my_fun1(B &);
connection con = bsignal.connect(bind(&my_fun1, _1));
using signals::trackable and signals::scoped_connection you
can have automatic connection management
you can group/order slots. you can chain signals. you can
now, of course you can implement all that functionality yourself.
the point is that you don't have to since someone else has done
Thanks for the explanation.
I think I just did not see the use for all this because I did not come
over a realworld application where this could be a perfect fit.
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