On quarta-feira, 22 de março de 2017 05:50:47 PDT Jean-Michaël Celerier wrote: > > QObject::bind(sender, &Sender::signalName, receiver, &Receiver::setter); > > > > This is exactly connect() we already have. > > I think that bind adds one more step : it does the set. ie. bind would be : > > QObject::bind(sender, &Sender::signalName, &Sender::getter, receiver, > &Receiver::setter); > > and would be equivalent to : > > QObject::connect(sender, &Sender::signalName, receiver, > &Receiver::setter); > receiver->setter(sender->getter());
The new value is already carried by the signal. We don't need the getter: my code examples already compile. > Now, about the overall string problem, I think that most people would > rather do : > > QObject::bind(sender, "source", receiver, "target"); > > And actually, with modern C++, this can be made typesafe : for instance the > boost.metaparse guys are > able to convert (constexpr) strings to types : > http://www.boost.org/doc/libs/1_63_0/doc/html/metaparse.html > at compile time. So it would not be unthinkable to have moc generate the > appropriate parser and "compile-time property" class As long as the property name is in a string, forget it. We need an actual C++ identifier with the property's type somewhere. As I said, that's either the getter or the signal. And since you can use the signal in connect()... > At the end of this mail there is an example implementation (that uses a > string literal from boost.hana) and allows to do the following at > compile-time: (requires c++17; I tested with clang 4 and I believe gcc 7 > would work) I'll just stop reading here. If it requires Clang 4 and GCC 7 and probably doesn't with with MSVC 2017, we can discuss this in 2023. > bind(sender, "source"_s, receiver, "compatibleTarget"_s); > > While this won't compile > > bind(sender, "source"_s, receiver, "incompatibleTarget"_s); > > So the SIGNAL() and SLOT() macros could maybe be modified this way (Qt6 > anyone ? ;p) to have compile-checked versions (SSIGNAL() / SSLOT()). Why? We have a perfectly working method that uses PMFs and delivers to callables, without additional magic. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
