PyG in C++

This is a minimal example of getting PyG to work in C++ with CMake.

In order to successfully compile this example, make sure you have both the C++ APIs of TorchScatter and TorchSparse installed.

For this, we need to add TorchLib to the -DCMAKE_PREFIX_PATH (run import torch; print(torch.utils.cmake_prefix_path) to obtain it). Then, e.g., to install TorchScatter, run:

git clone https://github.com/rusty1s/pytorch_scatter.git
cd pytorch_scatter
mkdir build && cd build
cmake -DWITH_CUDA=on -DCMAKE_PREFIX_PATH="..." ..
make
(sudo) make install

Once both dependencies are sorted, we can start the CMake fun:

1. Run save_model.py to create and save a PyG GNN model.
2. Create a build directory inside the current one.
3. From within the build directory, run the following commands:
   • cmake -DCMAKE_PREFIX_PATH="<PATH_TO_LIBTORCH>;<PATH_TO_TORCHSCATTER>;<PATH_TO_TORCH_SPARSE>" ..
   • cmake --build .

That's it! You should now have a hello-world executable in your build folder. Run it via:

./hello-world ../model.pt