PyBind11 Example After brew install

bindings.cpp

#include <pybind11/pybind11.h>
#include "kvstore.h"

namespace py = pybind11;

PYBIND11_MODULE(kvstore, m) {
    py::class_<KVStore>(m, "KVStore")
        .def(py::init<const std::string&>(), py::arg("path"))
        .def("put", &KVStore::put)
        .def("get", &KVStore::get);
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.14)
project(kvstore_python LANGUAGES CXX)

# ----------------------------
# 1) Find Python
# ----------------------------
find_package(Python COMPONENTS Interpreter Development REQUIRED)
message(STATUS "Python executable: ${Python_EXECUTABLE}")
message(STATUS "Python include dirs: ${Python_INCLUDE_DIRS}")

# ----------------------------
# 2) Find pybind11
# ----------------------------
# Option 1: Installed via pip
# You can set PYBIND11_DIR to your local pybind11 install
find_package(pybind11 CONFIG REQUIRED)
message(STATUS "Found pybind11: ${pybind11_INCLUDE_DIRS}")

# ----------------------------
# 3) Define extension module
# ----------------------------
pybind11_add_module(kvstore
    src/bindings.cpp
    src/kvstore.h
)

# ----------------------------
# 4) Set C++ standard
# ----------------------------
target_compile_features(kvstore PUBLIC cxx_std_17)

# Optional: add optimization flags
if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE Release)
endif()

kvstore.h

#include <optional>
#include <unordered_map>
#include <string>

class KVStore {
public:
    KVStore(std::optional<std::string> path = std::nullopt) {
        if (path) {
            file_path = *path;
        } else {
            file_path = "in_memory";
        }
    }
    void put(const std::string& key, const std::string& value) {
        store[key] = value;
    }

    std::string get(const std::string& key) const {
        auto it = store.find(key);
        if (it != store.end()) return it->second;
        return "";
    }

private:
    std::unordered_map<std::string, std::string> store;
    std::string file_path;
};