Just to add one more thing: since we create our own rootlogon.C, we could just add #define USE_DICT in there, and then cling would pick it up automatically. Unfortunately, there is no convenient solution yet for the ROOT Notebooks, since rootlogon.C is not picked up there… This creates another ‘boilerplate’ line of code for our users (see rootlogon.C not picked up by Jupyter C++ Notebooks)