I saw almost all (kinda exaggerated) projects using
ListView and TreeView will store user data in ItemData.

The regular method is casting a pointer of the user
data to and from DWORD_PTR, then using the Get(Set)ItemData
to store/retrieve the casted pointer, like this

struct MyData
{
// user data
};

MyData *data = new MyData
listview.SetItemData(0, (DWORD_PTR)data);

.... in other place,

MyData *data2 = (MyData*)listview.GetItemData(0);

Could WTL add a new template parameter to CListViewCtrlT
like this:

template <class TBase, class TData=DWORD_PTR>
class CListViewCtrlT : public TBase
{
....
TData GetItemData(int nItem) const
{
....
}

BOOL SetItemData(int nItem, TData dwData)
{
....
}
...
}

then we can use CListViewCtrlT in this way:

CListViewCtrlT<CWindow,MyData*> listview;

MyData *data = new MyData
listview.SetItemData(0, data);

.... in other place,

MyData *data2 = listview.GetItemData(0);

Thus, no cast needed. How do you think about it?


Best Regards
gchen