lifetime issue in pybind

[noajshu]

Describe the issue

Trying to diagnose symptoms of a memory leak in the python interface and wondering if it's because we're returning C++ memory here:

tesseract-decoder/src/tesseract.pybind.h

Line 234 in 1e0cd87

return self.predicted_errors_buffer;

Note that pymatching returns the pybind array instead:
https://github.com/oscarhiggott/PyMatching/blob/c60642af5a5b342d633e2e2b818b9fdb9696e828/src/pymatching/sparse_blossom/driver/user_graph.pybind.cc#L200-L217

What version of the software are you using?

No response

How can the issue be reproduced?

No response

[NoureldinYosri]

if I understand correctly, there is an increase in memory use at that call, right? I think this is because that return statement copies the content of the vector to a python array so there is a moment where there are two copies of the data

we should use a pybind11:capsule and pybind11::array_t instead, the same way as pymatching https://github.com/oscarhiggott/PyMatching/blob/c60642af5a5b342d633e2e2b818b9fdb9696e828/src/pymatching/sparse_blossom/driver/user_graph.pybind.h#L37