pybind11 与 C++ 绑定类和回调函数的交互

代码结构
----3rdparty
------pybind11 # 存放 pybind11编译好后的文件夹
—build
------test.py # 测试文件
—include
------calculator.h # 计算器类
—src
------calculator.cpp
-------example.cpp # 绑定计算器类的例子
—CMakeLists.txt

pybind11 怎么安装可以另行搜索，或者留言，根据实际情况我会再写教程。
编译环境 centos7 64
calculator.h

#include<string>
#include<functional>

class calculator
{
public:
    calculator();
    ~calculator();
    double add(double a, double b);
    double sub(double a, double b);
    double mult(double a, double b);
    double div(double a, double b);
    void setName(std::string name);
    std::string getName();
    void registerCallBack(std::function<void(int)> &handler);
private:
    std::string name;
    std::function<void(int)> m_handler = nullptr;
};

calculator.cpp

#include<calculator.h>

calculator::calculator()
{

}
calculator::~calculator()
{
    
}
double calculator::add(double a, double b)
{
    if (m_handler) {
        m_handler(a + b);
    }
    return a + b;
};
double calculator::sub(double a, double b)
{
    if (m_handler) {
        m_handler(a - b);
    }
    return a - b;
};
double calculator::mult(double a, double b)
{
    if (m_handler) {
        m_handler(a * b);
    }
    return a * b;
};
double calculator::div(double a, double b)
{
    if ((int)b == 0 ) {
        if (m_handler) {
            m_handler(0XFFFFFFFF);
        }
        return 0XFFFFFFFF;
    }
    if (m_handler) {
        m_handler(a / b);
    }
    return a / b;
};
void calculator::setName(std::string name)
{
    this->name = name;
}
std::string calculator::getName()
{
    return this->name;
}

void calculator::registerCallBack(std::function<void(int)> &handler)
{
    m_handler = handler;
}

example.cpp

#include <pybind11/pybind11.h>
#include <iostream>
#include <calculator.h>
#include <pybind11/stl.h>
#include <pybind11/complex.h>
#include <pybind11/functional.h>
#include <pybind11/chrono.h>

namespace py = pybind11;

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

const char* helloworld()
{
    return "hello world";
}
int  h()
{
    return 9999;
}
PYBIND11_MODULE(engine, m) {
    m.doc() = "pybind11 engine plugin"; // optional module docstring
    m.def("add", &add, "A function which adds two numbers");
    m.def("hello", &helloworld, "hello world");
    m.def("h9", &h, "h");

    py::class_<calculator>(m, "calculator")
    .def(py::init())
    .def_property("name", &calculator::getName, &calculator::setName)
    .def("setName", &calculator::setName)
    .def("getName", &calculator::getName)
    .def("add", &calculator::add)
    .def("sub", &calculator::sub)
    .def("mult", &calculator::mult)
    .def("div", &calculator::div)
    .def("registerCallBack", &calculator::registerCallBack);
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)

project(pyCode)

set(CMAKE_CXX_STANDARD 11)

include_directories("include")

file(GLOB SRCS 
    src/example.cpp
    src/calculator.cpp
	)

add_subdirectory(3rdparty/pybind11)
pybind11_add_module(engine ${SRCS})

test.py

import engine;

def handle_message(value):
    print("handle_message is ", value)

cc = engine.calculator()
cc.registerCallBack(handle_message)


while True:
    a = float(input("plase input value: a:"))
    b = float(input("plase input value: b:"))
    cc.add(a, b)
    cc.sub(a, b)
    cc.div(a, b)
    cc.mult(a, b)

编译：
cd build
cmake …
make -j
以上生成 engine.cpython-36m-x86_64-linux-gnu.so
执行:

总结：
pybind11 方便的实现了C++与python的交互，回调也不成问题，如果加上TCPIP等网络协议，就可以实现多进程多语言的交互，实现了多组件之间的通信。