OnceCallback: Callback Design Lessons from Chromium

This directory systematically covers the design of modern C++ callback systems by implementing a Chromium-style OnceCallback component. The content is divided into two learning paths:

Complete Beginner Tutorial (full/)

Tailored for readers with no prior experience, starting with a review of fundamental C++ features and gradually guiding them to a complete component implementation.

Prerequisites (7 chapters):

OnceCallback Prerequisites Quick Reference: Review of C++11/14/17 Core Features→OnceCallback Prerequisites (Part 1): Function Types and Template Partial Specialization→OnceCallback Prerequisites (Part 2): std::invoke and the Unified Callable Protocol→OnceCallback Prerequisites (Part 3): Advanced Lambda Features→OnceCallback Prerequisites (Part 4): Concepts and requires Constraints→OnceCallback Prerequisites (Part 5): std::move_only_function (C++23)→OnceCallback Prerequisites (Part 6): Deducing this (C++23)→

Hands-on Practice (6 chapters):

OnceCallback in Practice (Part 1): Motivation and API Design→OnceCallback in Practice (Part 2): Building the Core Skeleton→OnceCallback in Practice (Part 3): Implementing bind_once→OnceCallback in Practice (Part 4): Cancellation Token Design→OnceCallback in Practice (Part 5): then Chaining Composition→OnceCallback in Practice (Part 6): Testing and Performance Comparison→

Advanced Design Guide (hands_on/)

Tailored for readers experienced with C++ templates, providing a quick walkthrough of the design motivation, implementation strategies, and test verification.

once_callback Design Guide (Part 1): Motivation and API Design→once_callback Design Guide (Part 2): Step-by-Step Implementation→once_callback Design Guide (Part 3): Testing Strategies and Performance Comparison→