Using QStack, how to remove at specific location.

[SPlatten]

I am using a QStack to create an undo / redo stack:

    class clsQtJsonStack : public QStack<QJsonObject> {
    private:

    public:
        clsQtJsonStack();
        int intPush(const QJsonObject& crJSON);
    };

As I edit a control the data is pushed onto the stack. When I undo I take the data from the last undo position, using at. This doesn't remove the item from the stack, how should I do this because looking at the documentation there doesn't appear to be a call to remove an item at a specific index.

Looking at how to use remove and removeAt, the documentation isn't create because both these expect a qsizetype parameter, is this just an integer cast as qsizetype ?

[Christian Ehrlicher]

@SPlatten said in Using QStack, how to remove at specific location.:

This doesn't remove the item from the stack, how should I do this because looking at the documentation there doesn't appear to be a call to remove an item at a specific index.

If it would have those function than it wouldn't be a stack. If you want to remove at a specific index use the proper container.

[SPlatten]

@Christian-Ehrlicher , according to the documentation:
https://doc.qt.io/qt-6/qstack.html

The class is derived from QList, QList does have remove:
https://doc.qt.io/qt-6/qlist.html#remove

And removeAt:
https://doc.qt.io/qt-6/qlist.html#removeAt

[JonB]

@SPlatten
Then you can use the methods derived from QList. In fact, if you are removing at arbitrary position it is a list rather than a stack anyway, so use that. For a stack you should just use push() and pop().

As I edit a control the data is pushed onto the stack. When I undo I take the data from the last undo position, using at. This doesn't remove the item from the stack, how should I do this because looking at the documentation there doesn't appear to be a call to remove an item at a specific index.

This is just T QStack::pop(), and you don't need any *remove at specific index".

Yes the methods which take a qsizetype as an index accept an integer.

[Axel Spoerl]

@SPlatten: I agree with @Christian-Ehrlicher - it looks scary to remove items from the middle of a stack.
As you have correctly noticed, QStackis a thin wrapper around QList, which provides access to all its container functions.
In your research about those, you were just one double click away from the answer to your actual question: qsizetypeis a signed version of size_t.
using qsizetype = QIntegerForSizeof<std::size_t>::Signed;