Dependency Injection in C++ - A Practical Guide

Learn about dependency injection principles and implementation in C++ through this conference talk from C++ on Sea 2024. Explore essential building blocks including link-time substitution, dummies, inheritance-based interfaces, templates, smart pointers, and polymorphic function wrappers while understanding their strengths, weaknesses, and optimal use cases. Master practical strategies for injecting multiple dependencies without relying on singletons or global state, and discover techniques for introducing dependency injection into legacy codebases with minimal disruption. Drawing from over 30 years of C++ experience, gain insights into applied engineering principles that promote testable, extensible, and well-structured code through practical examples and real-world scenarios. Examine what constitutes effective dependency injection and develop a coherent strategy for implementing these patterns in your own applications.