How to Utilize C-Style Function Pointers with Pybind11

Introduction to the Concept

Delve into the realm of utilizing C-style function pointers in Python with the help of Pybind11. This tutorial explores the seamless integration of C++ and Python, offering a blend of efficiency from C++ and versatility from Python. By leveraging Pybind11, you can bridge the gap between these two languages and enhance your code execution capabilities.

What You’ll Learn

Discover the essence of function pointers in C and how they can be harnessed within Python scripts using Pybind11. Gain insights on amalgamating these distinct paradigms for enhanced code efficiency.

Bridging C++ and Python with Pybind11

Function pointers in C store function addresses for later invocation, a concept that may seem distant from Python’s dynamic nature. However, Pybind11 acts as a bridge, enabling seamless connectivity between these worlds. Here’s what you will explore: 1. Defining a simple function in C++ to be called from Python using a function pointer. 2. Integrating this setup into a cohesive system using Pybind11.

Our objective is twofold: showcase the ease of incorporating native C++ functionality into Python applications and provide a detailed example illustrating this integration process step by step.


#include <pybind11/pybind11.h>

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

namespace py = pybind11;

PYBIND11_MODULE(example_module, m) {
    m.def("add", &add);

# Copyright PHD

The code snippet above demonstrates creating a basic module in C++ with Pybind11, exposing the add function for access from Python.


In our example: 1. Function Definition: The add function simply adds two integers. 2. PyBind Module Declaration: Using PYBIND11_MODULE, we declare our module (example_module) accessible in Python. 3. Exposing Functions: With .def(), we make our add method callable like any other native Python function when imported.

By encapsulating critical parts of your application within native modules like this, you leverage both languages’ strengths without compromising speed or usability.

  1. How do I install PyBind?

  2. To install PyBind, use pip:

  3. pip install pybind11
  4. # Copyright PHD
  5. Can objects be passed between C++ and Python?

  6. Yes! Objects can seamlessly move between both domains due to automatic type conversions provided by PyBind.

  7. Is multithreading supported with PyBind?

  8. Indeed! While ensuring thread safety is crucial, multithreading is supported when working with PyBind.

  9. Can I call Python callbacks from exposed functions?

  10. Absolutely! You can pass down and invoke callbacks defined in Python from your compiled module effortlessly.

  11. Do I need extensive knowledge of both languages?

  12. While familiarity helps, basic knowledge suffices; understanding specific interaction patterns might be necessary for more complex scenarios.


By blending high-level scripting languages like Python with low-level systems programming languages such as C++, developers unlock new possibilities for software projects seeking performance optimization while maintaining ease-of-use through higher-level abstractions. Technologies like PyBind play a pivotal role in facilitating seamless integrations across diverse technological ecosystems, broadening horizons for modern software solutions.

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