ESSENTIALS 010-003 scope description?

[Houd1ny]

Hi, Qt team

I am preparing for certification. i`m not sure what is required to know according to this sentence "Understand the central role of QVariant for many other container classes "
I have read some articles and docuentation.(1, 2, 3, 4, 5) And I can not find anything about central role for containers. Contenders are template classes how should they care about QVariant.
Could someone specify what is required here?

[SGaist]

Hi and welcome to devnet,

Another excellent article that's worth reading is Type Erased Container Iteration.

I'm not sure I understand that phrase correctly. However the use of QVariant to transfer complex data from one point to another comes to mind. And you can use QVariant based container when you want to pass heterogeneous data from one class to another.

Hope it helps.