connect() does not take signalMapper as slot

[dalishi]

Hi, I'm using almost the same code from QSignalMapper document

signalMapper = new QSignalMapper(this);
QPushButton *button = new QPushButton("test");
connect(button, &QPushButton::clicked, signalMapper, &QSignalMapper::map);

However I got error:

configdialog.cpp:89:5: No matching member function for call to 'connect'
qobject.h:222:36: candidate function not viable: no known conversion from 'void (QAbstractButton::*)(bool)' to 'const char *' for 2nd argument
qobject.h:225:36: candidate function not viable: no known conversion from 'void (QAbstractButton::*)(bool)' to 'const QMetaMethod' for 2nd argument
qobject.h:481:41: candidate function not viable: no known conversion from 'void (QAbstractButton::*)(bool)' to 'const char *' for 2nd argument
qobject.h:242:43: candidate template ignored: couldn't infer template argument 'Func2'
qobject.h:283:13: candidate template ignored: couldn't infer template argument 'Func2'
qobject.h:322:13: candidate template ignored: couldn't infer template argument 'Func2'
qobject.h:274:13: candidate function template not viable: requires 3 arguments, but 4 were provided
qobject.h:314:13: candidate function template not viable: requires 3 arguments, but 4 were provided

My other connect() works all fine except QSignalMapper. Am I not using it correctly? Thanks.

[JonB]

@dalishi
I think: We are dealing with overloads of QSignaller::map() method. Doc example may not be up-to-date? Try:

QOverload<>::of(&QSignalMapper::map)

Does that fix?
See https://stackoverflow.com/questions/68552698/connecting-qsignalmapper-qt-5-15-2.

[mrjj]

JonB beat me to it. :)

connect(button, &QPushButton::clicked, signalMapper, qOverload<>(&QSignalMapper::map) );

[JonB]

@mrjj So are you volunteering to report it as a docs bug? :) Or @dalishi may care to do so.

[dalishi]

@JonB Hi thanks for the reply. It seems working at least syntax-wise :)

[dalishi]

@mrjj it seems we need ::of here as in @JonB 's post. Otherwise we get the error:

configdialog.cpp:91:71: Address of overloaded function 'map' does not match required type 'QOverload<>'
qsignalmapper.h:85:10: candidate function
qsignalmapper.h:86:10: candidate function

and it is QOverload<> not qOverload<> tho, haha, thanks.

[dalishi]

@JonB i reported a bug but im first time so not sure whether im doing it correctly. Link is here

[JonB]

@dalishi
All good, looks fine. I appended a post to clarify what exactly the statement in the example should read.