I’m following the https://pytorch.org/tutorials/advanced/torch_script_custom_classes.html in order to expose my C++ dll in Python.
The bulk of the code that I have at the moment is this :
#include <string>
#include <vector>
#include <torch/script.h>
include <FV/FV.h>

struct PyManager : torch::CustomClassHolder {
    PyManager(std::string model, std::string root, std::string cache, bool rebuildCache) 
    {
        auto config = FV::Load_Default_Settings();
        config.mutable_configuration()->mutable_x()->mutable_settings()->set_x_rebuild_cache(rebuildCache);
        config.mutable_configuration()->mutable_x()->mutable_settings()->set_x_cache_folder(cache_folder);
        //... some other settings being set using protobuf config here
        fv = std::make_shared<FV>(config);
    }

    int AddUser(std::string user_id, std::string path) 
    {
        fv->AddNewUser(user_id, path);
    }
    int RemoveUser(std::string user_id) 
    {
        fv->RemoveUser(user_id);
    }
    int UpdateUser(std::string usier_id, std::string new_path)
    {
        fv->UpdateUser(usier_id, new_path);
    }
    int UpdateUsersInBulk(std::vector<std::string> userIDs, std::string path, bool is_delete_granted = true, bool show_dbg_info = true)
    {
        fv->UpdateUsersInBulk(userIDs, path, is_delete_granted, show_dbg_info);
    }
    int RenameId(std::string old_id, std::string new_id)
    {
        fv->RenameUserID(old_id, new_id);
    }

private:
    std::shared_ptr<FV> fv;
};

TORCH_LIBRARY(my_classes, m) {
    m.class_<PyManager>("PyManager")
        .def(torch::init<std::string, std::string, std::string, bool>())

        .def("add", &PyManager::AddUser)
        .def("remove", &PyManager::RemoveUser)
        .def("update", &PyManager::UpdateUser)
        .def("update_in_bulk", &PyManager::UpdateUsersInBulk);
}

And this is the cmake file that I use :
cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
project(custom_class)

find_package(Torch REQUIRED)
find_package(Protobuf REQUIRED)

INCLUDE_DIRECTORIES(
"D:/Codes/cpp/port/LibtorchPort/Dependencies/include"
"D:/External Libs/Opencv3.4.10_vc14_vc15/opencv3.4/include"
)

LINK_DIRECTORIES(
"D:/Codes/cpp/port/LibtorchPort/x64"
"D:/External Libs/Opencv3.4.10_vc14_vc15/opencv3.4/x64/vc14/lib"
)

# Define our library target
add_library(custom_class SHARED class1.cpp)

#define our c++ standard
set(CMAKE_CXX_STANDARD 17)
# Link against LibTorch
target_link_libraries(custom_class "${TORCH_LIBRARIES}")

and I’m calling cmake like this :
cmake -DCMAKE_PREFIX_PATH="$(python -c 'import torch.utils; print(torch.utils.cmake_prefix_path)')" ..

but I get the following error :
Severity	Code	Description	Project	File	Line	Suppression State
Error	C2338	INVALID TYPE: Only int64_t and bool are supported as an integral argument type	custom_class	D:\Codes\cpp\port\LibtorchPort\Dependencies\libtorch-debug-latest\libtorch\include\ATen\core\op_registration\infer_schema.h	39	

What am I missing here ?
Any help is greatly appreciated