How to Set QNNPACK as Quantization Backend in C++ for PyTorch on Raspberry Pi 4?

I’m transitioning from Python to C++ for deploying a quantized model on an rpi4 device and aiming to achieve maximum inference speed. In Python, setting torch.backends.quantized.engine = 'qnnpack' significantly improves my model’s FPS performance, it boosts from ~4 FPS to ~45 FPS.

How can I achieve a similar backend switch to QNNPACK in C++?
Is there any C++ equivalent to:
`torch.backends.quantized.engine = ‘qnnpack’?

Thank you in advance,


#include <ATen/ATen.h>
#include <torch/torch.h>

int main() {
// Set the quantization engine to QNNPACK
return 0;