Python-C++ Bindings Meeting

Tuesday 7 Apr 2026, 16:00 → 17:00 Europe/Zurich

Aaron Jomy (CERN)

Discussion on developments in Python-C++ bindings surrounding the Cppyy project, and broader interactive C++ as a service based on the CppInterOp project.

Vipul, Vincenzo and Emery off.

Roundtable:

Aaron:
  * Continued with the ROOT migration effort to new cppyy
  * Helping Vassil to set up NUC for CI environment
  * Worked on the demo for EuroLLVM

Vassil:
  * Talked with Emery about looking into the iterator stuff
  * Looked into the cppyy ROOT migration, surprised about all the diagnostics
    that are printout, need to investigate that
      * Want to implement diagnostic suppression properly
      * Sould be improved at the same time as fixing up LLVM initialization and
        shutdown
  * Implemented short path resolution logic for builtin types

Jonas:
  * Fixed some ROOT Python interface GitHub issue
  * Added support for Python 3.15
  * Thinking about clear API boundaries for CppJIT C API, which right now
    groups "module" functions for use in other CPython extensions and "Python
    interpreter embedding" functions together (from TPython).
    * For module API, we should move to CPython capsules:
      https://docs.python.org/3/c-api/capsule.html
    * About the interpreter embedding API, we need to decide what we actually
      want to keep

Silia Taider:
  * Fixing reported problems about the ML data loader
  * Reviewing PRs

Yasser (CTC):
  * Not much since Emery is not there
  * The last blockers are the iterator test, the enums, and the strange map
    problem all reported by Emery, and then the new cppyy/CppJIT would be
    production ready
  * The tests were added here:
    https://github.com/compiler-research/cppyy/commit/c9c5e576a71170ea9affe53fb8ba3fe4f0f2dd42

1 Round Table

2 AOB