[Bug] soxr-1.0.0 won't complie

[randynovak]

Version

2.0.0 (Default)

System Information

Python 3.10.18
soxr-1.0.0.
gcc version 7.3.1 20180712 (RedHat 7.3.1-17) (GCC)
Target: x86_64-redhat-linux

Description

The Problem

The core issue was with how C++ template functions were being bound to Python using nanobind. The original code was trying to directly bind template functions like this:

.def("process_float32", &CSoxr::process)

This approach doesn't work well with nanobind because:

1. C++ template functions need to be explicitly instantiated for binding
2. The compiler couldn't deduce the template parameters when binding directly
3. Template specializations can't be directly used as function pointers in this context

How to Reproduce the Bug

The problem persists until solved, below.

The Solution

Replaced all direct template function bindings with lambda functions that explicitly call the template functions with the correct types:
.def("process_float32", [](CSoxr& self, ndarray<const float, nb:ndim<2>, nb::c_contig, nb::device::cpu> input, bool last=false) {
return self.process(input, last);
})

This approach works because:

1. The lambda function is not a template - it's a concrete function that nanobind can bind
2. Inside the lambda, we explicitly call the template function with the specific type
3. The lamba's parameter types exactly match what the template function expects
4. This pattern provides a "bridge" between Python and the C++ template functions

Applied this pattern consistently to all template functions in the binding code, ensuring that each one is properly instantiated with its specific type.
This is a common pattern when binding C++ template functions to Python, as most binding libraries (including nanobind, pybind11, etc.) require explicit instantiation of templates.

[randynovak]

For clarification: soxr-1.0.0/src/soxr_ext.cpp

[ereoh]

To clarify, are you trying to run some C++ code with torchsig? Torchsig at its core does not have any C++ code. However, if this is related to our rust code please let me know.

[randynovak]

To clarify, are you trying to run some C++ code with torchsig? Torchsig at its core does not have any C++ code. However, if this is related to our rust code please let me know.

No custom code, simply rebuilding TorchSig v2.0.0 out of the box. Cited the issue here: #416

When I pip install torchsig locally, it failed with the soxr error that I had to patch locally in order for torchsig to build. I saw the error when using soxr version 1.0.0 that I ended up patching.

With respect to Rust, I had on-prem issues prior in getting the Rust crates loaded up but I got them loaded locally to process forward before running into the soxr issue. So it may be related to Rust, I don't know enough to answer that question but I did build the Rust baseline prior to pip install torchsig. Maybe that is where the issue came up in my build and couldn't bind with soxr.