Bug: Python serialized_length property raises TypeError due to missing default argument

[titusz]

Describe the bug

The serialized_length property on the Python Index class raises a TypeError when accessed. The pybind11 binding doesn't expose the default argument for the serialization_config_t parameter, so Python callers cannot use the property without explicitly providing a config object (which isn't possible via the property interface).

The binding in python/lib.cpp:

i.def_property_readonly("serialized_length", &dense_index_py_t::serialized_length);

The C++ method signature in index_dense.hpp:

std::size_t serialized_length(serialization_config_t config = {}) const

Suggested fix - wrap in a lambda:

i.def_property_readonly("serialized_length", [](dense_index_py_t const& self) { 
    return self.serialized_length(); 
});

Steps to reproduce

from usearch.index import Index, MetricKind, ScalarKind
import numpy as np

idx = Index(ndim=32, metric=MetricKind.Hamming, dtype=ScalarKind.B1)
idx.add(1, np.array([178, 204, 60, 240], dtype=np.uint8))

# This raises TypeError
result = idx.serialized_length

Error:

TypeError: (): incompatible function arguments. The following argument types are supported:
    1. (arg0: usearch.compiled.Index, arg1: unum::usearch::index_dense_serialization_config_t) -> int

Invoked with: <usearch.compiled.Index object at 0x...>

Expected behavior

idx.serialized_length should return an integer representing the serialized length in bytes, using the C++ default config value.

USearch version

v2.21.0

Operating System

Windows 11 (also reproduced on Linux)

Hardware architecture

x86

Which interface are you using?

Python bindings

Searched existing issues

I have searched existing issues and this hasn't been reported.

Code of Conduct

I agree to the Code of Conduct.

[ashvardanian]

Thanks, @titusz! The proposal makes sense - feel free to open a PR 🤗