Add generic wrapper for iterators.
Add generic wrapper for iterators.

NicolasSchnitzler/dtk,rdebroiz/dtk,d-tk/dtk,d-tk/dtk,rdebroiz/dtk,rdebroiz/dtk,rdebroiz/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,NicolasSchnitzler/dtk,NicolasSchnitzler/dtk,d-tk/dtk,NicolasSchnitzler/dtk