=?utf-8?q?Suggestion=3a=20Leverage=c2=a0std=3a=3aoptional=20to=20indicate=20whether=20CListViewCtrlT=3c=3e=20and=20CTreeViewCtrlT=3c=3e=20GetItemData=28=29=20member=20functions=20return=20a=20valid=20value=20or=20not?=

[Simon Said]

Hello,

Because GetItemData() implementation for both CListViewCtrlT<> and
CTreeViewCtrlT<> returns 0 (NULL) when the call to SendMessage() fails,
it is not possible to know whether 0 represents a valid item data value
or an error code. The suggested changes leverage c++ 17 std::optional
https://www.bfilipek.com/2018/05/using-optional.html class to make
that distinction.

See attachement,

Thanks,

Simon-Pierre