pybind/pybind11

Support for dataclasses

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#2065 opened on Jan 10, 2020

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enhancementhelp wanted

Description

pybind11 talks of course about how to wrap C++ classes so that they are accessible in python. The issue for me is that on the python side of things, we are using dataclasses very extensively. They provide a lot of useful built in features as well as type annotations that you can use with mypy. If you are wrapping a C++ class, then obviously, all the types are already present, so in principle it would be possible at no extra cost to export a dataclass rather than a regular python class, which would be really useful.

Maybe this is not possible to do from a purely C/C++ module, but if it is it would be pretty amazing.

Contributor guide

Tech stack
pythoncpp
Domain
developer experience
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
pybind11 internalsPython C APIPython dataclassesC++ template metaprogramming
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
Investigate pybind11's current class wrapping mechanism, particularly the `py::class ` template and how it generates Python type objects. Study Python's `dataclasses` module to understand required attributes. Consider whether it's possible to modify pybind11 to add `@dataclass` decorator or equivalent attributes at runtime. Look for any existing PRs or discussions in the pybind11 repository regarding dataclasses.