error: no matching function for call to 'QList<QObject *>::removeAll()'

Calvin H-C

I have a class that has several private members that have type QObjectList:

QObjectList	A,
		B,
		C,
		D;

The class has a delete function for each of these object lists that deletes each item in the list, then removes them from the list:

void ClassName::DeleteA()
{
	for( int i = A.count(); i--; )
		delete *Output[ i ];
	A.removeAll();
}

I'm getting a "error: no matching function for call " error for the call to removeAll() or each function. The error remains if I remove the delete loop and only have the removeAll() call.

If it helps, I'm using the Desktop Qt 5.15.2 MinGW 32-bit compiler.

SGaist

Hi,

Here is a shorter version:

qDeleteAll(myContainer);
myContainer.clear();

qDeleteAll

jeremy_k

@Calvin-H-C said in error: no matching function for call to 'QList<QObject *>::removeAll()':

I have a class that has several private members that have type QObjectList:
QObjectList	A,
		B,
		C,
		D;
The class has a delete function for each of these object lists that deletes each item in the list, then removes them from the list:
void ClassName::DeleteA()
{
	for( int i = A.count(); i--; )
		delete *Output[ i ];

Not that this is particularly tricky code, but
qDeleteAll() is another option.

A.removeAll();
}

You probably want QList::clear().
QList::removeAll() takes a parameter specifying a value to remove.

Pl45m4

@Calvin-H-C said in error: no matching function for call to 'QList<QObject *>::removeAll()':

"error: no matching function for call "

Because there is no such function in the way you are trying to use it.

QObjectList is an alias for a list storing QObject pointers, so: QList<QObject* >.
QList has the function removeAll which signature is:

QList::removeAll(const AT &t)
(https://doc.qt.io/qt-6/qlist.html#removeAll)

Since you want to delete every member of that list manually before, why dont you simply call A.clear()?

Or use it together with takeAt(i) like

for( int i = A.count(); i--; ){
   auto obj = A.takeAt(i);
   delete obj;
}
A.clear();

@jeremy_k took me a while to write this post. You were faster sending the answer :P

jeremy_k

@Pl45m4 said in error: no matching function for call to 'QList<QObject *>::removeAll()':

@jeremy_k took me a while to write this post. You were faster sending the answer :P

Competition-grade keyboard!

SGaist

Hi,

Here is a shorter version:

qDeleteAll(myContainer);
myContainer.clear();

qDeleteAll

Calvin H-C

@SGaist said in error: no matching function for call to 'QList<QObject *>::removeAll()':

qDeleteAll(myContainer);
myContainer.clear();

Thanks to everyone, but especially for this concise suggestion.

Somewhere I did see that removeAll() was for all of a specific value, but somehow forgot that little detail. Just all part of using MFC for many years before learning QT in my late 50s.

JonB

@Calvin-H-C
The sample code at https://doc.qt.io/qt-6/qtalgorithms.html#qDeleteAll gives just that code :)