Connect signal lambdas trouble
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I'm trying to hook a couple of lambdas to connect for some sig/slots, one works but the other won't compile.
This is the working one.
@QProcess *process = new QProcess(this);
connect(process, &QProcess::readyReadStandardOutput, {
qDebug("StdOut!");
});@and this one won't compile
@ connect(process, &QProcess::finished, [](int exitCode, QProcess::ExitStatus exitStatus) {
qDebug("Done!");
});@I'm 100% sure the lambda signature matches but not sure why it's picking one connect overload over the working one. Any ideas?
@D:\Dev\SanityCheck\sanity.cpp:30: error: C2664: 'QMetaObject::Connection QObject::connect(const QObject *,const char *,const char *,Qt::ConnectionType) const' : cannot convert parameter 2 from 'overloaded-function' to 'const char *'
Context does not allow for disambiguation of overloaded function@This is all using VS2012 as the compiler. Any pointers appreciated.
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Hi, and welcome to the Qt Dev Net!
You need to make an explicit cast to tell your compiler which overload to use.
@
void (QProcess::*mySignal)(int, QProcess::ExitStatus) = &QProcess::finished;connect(process, mySignal, [](int exitCode, QProcess::ExitStatus exitStatus)
{
qDebug("Done!");
});
@Above, mySignal is the name of a local variable (a function pointer). You can use a different name if you want.
Or, you can also do an inline cast without storing the function pointer:
@
connect(process,
static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished),
[](int exitCode, QProcess::ExitStatus exitStatus)
{
qDebug("Done!");
});
@
