Subclass QList<T>

[Seishin]

Hi,

I want to make a subclass of QList for any type T.

Since I'm not very familiar with templates inheriting, I try to make a mirror copy of QList first.

This is my my_list.h header file

template <class T>
class MyList : public QList<T>
{
public:
    MyList() : QList() {}
    ~MyList() : ~QList() {}
};

template <class T>
class MyList : public QList<T>
{
public:
    MyList() : QList() {}
    ~MyList() : ~QList() {}
};

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I try to use MyList as a QList in the main program, but the code cannot be compiled.
The error is :

error C2059: syntax error : '~' while compiling class template member function 'MyList<T>::~MyList(void)' with [ T = MyObject *]
                  see reference to class template instantiation 'MyList<T>' being compiled with [ T = MyObject *]

error C2059: syntax error : '~' while compiling class template member function 'MyList<T>::~MyList(void)' with [ T = MyObject *]
                  see reference to class template instantiation 'MyList<T>' being compiled with [ T = MyObject *]

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How should I fix the error to create a template works exactly as QList?
Thanks in advance.

[ChrisW67]

I want to make a subclass of QList for any type T.

QList already is list of arbitrary type T. It already is a template class.

[Santosh Reddy]

Base class destructor should not be called (it is internally called implicitly)

//~MyList() : ~QList() {}
~MyList() {}

//~MyList() : ~QList() {}
~MyList() {}

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[Seishin]

QList already is list of arbitrary type T. It already is a template class.

You are right. But I want to override some function of QList later, so I try to make a simple copy subclass first.

[ChrisW67]

QList is not designed to be inherited and have its behaviours overridden: it has no virtual functions. Its destructor is not virtual so polymorphic pointers (if you were intending to use them) will also be dangerous. You could add behaviours like QStringList does.

You usually better off either using QList<T> as-is or incorporating it by composition rather than inheritance.