When you forget C++ but still want that 10x speedup
A thin wrapper around OpenAI Codex that prompts an LLM to rewrite your Python as C++, then tries to compile the result.

What it does
Feed it a .py file and it builds a prompt for OpenAI Codex asking for a C++ translation. If the returned code compiles with g++, you get a .cpp source and a .exe binary. The README shows a toy example: a two-argument add_something function with some cout strings.
The interesting bit
The whole “compiler” is really just prompt engineering plus subprocess.call(g++). The actual heavy lifting—semantic analysis, type inference, memory management decisions—is delegated to a black-box LLM. It’s a neat demonstration of how far you can get with zero static analysis and a prayer.
Key highlights
- Single-file converter:
python2cppconverter.pydoes the prompt construction and compilation check - Requires private Codex API access (not the public ChatGPT API)
- Successful compilations are cached as
.cpp+.exe; failures are silently discarded - Includes a
timecomparison workflow to check if you actually gained speed - Explicitly marked work-in-progress by the author
Caveats
- Author warns: “does not produce robust code conversions”
- No test suite, no verification that outputs match beyond manual
diff - Codex API access is gated and may change or disappear
Verdict
Worth a look if you’re experimenting with LLM code generation or need a classroom demo of “what if we just asked an AI to transpile?” Anyone shipping production code should probably learn C++ the old-fashioned way—or reach for Cython, mypyc, or Rust bindings instead.