pybind11 build tutorial

#pybind11
https://bayareanotes.com/pybind-tutorial/
对于以下的模块示例代码，我们可以通过多种方法将这个module编译生成python可以直接调用的module，这里我们简单介绍三种比较常用的方法


#include <pybind11/pybind11.h>

int add(int i, int j) {
    return i + j;
}

PYBIND11_MODULE(example, m) {
    m.def("add", &add, "A function which adds two numbers");
}

1. build with python setup

setup.py

from setuptools import setup, Extension

module = Extension('example', sources=['example.cpp'])

setup(
    name='example',
    version='1.0',
    ext_modules=[module],
)

编译生成对应的模块python setup.py build_ext --inplace

2. build with cmake

创建CMakeLists.txt文件

cmake_minimum_required(VERSION 3.0)
project(pybind11_example)

# Find Python
find_package(PythonLibs REQUIRED)
include_directories(${PYTHON_INCLUDE_DIRS})

# Find Pybind11
find_package(pybind11 REQUIRED)

# Add the example module
pybind11_add_module(example example.cpp)

# Link the module with Python
target_link_libraries(example PRIVATE ${PYTHON_LIBRARIES})

编译模块mkdir build && cd build && cmake .. && make

3. build manually

https://pybind11.readthedocs.io/en/stable/compiling.html#building-manually

## for linux
c++ -O3 -Wall -shared -std=c++11 -fPIC $(python3 -m pybind11 --includes) example.cpp -o example$(python3-config --extension-suffix)
## for macOS
c++ -undefined dynamic_lookup  -O3 -Wall -shared -std=c++11 -fPIC $(python3 -m pybind11 --includes) example.cpp -o example$(python3-config --extension-suffix)