Thiago Macieira wrote:

> On Wednesday, 21 de September de 2011 15.12.21, Thiago Macieira wrote:
>> There's no way around it. Since we're using the function pointer
>> (actually, the PMF) to identify the signal, you must have C++ access to
>> the signal function. That means you must be able to call it.
>> 
>> Other template-based signal libraries have the same problem. It cannot be
>> avoided unless you have a way to identify the signal which doesn't
>> include access to the actual signal implementation.
>> 
>> One solution to that would be to have an enum of signals, instead of
>> identifying by an object or by a PMF.
> 
> Another solution (also by way of adding an indirection) is to add a
> function that emits, which is protected.
> 
> template <typename Klass, typename... Args>
> void QObject::emitSignal(void (Klass:: *signal)(Args...), Args... args);
> 
> Then you'd write:
> emitSignal(&Me::textChanged, newText);
> instead of:
> emit textChanged(newText);
> 
> The template magic to make that happen is already present.
> 
> However, it would be completely source-incompatible with the existing
> code, which is a big no-no. It would require making the signal functions
> themselves not do anything -- only serve as identifiers.
> 

For source compatibility they could be implemented by moc to work as 
currently, no?

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