Spooky Action at a Distance - Revisiting C++ Observers

Explore the intricacies of the Observer pattern in C++ through this comprehensive conference talk from ACCU 2023. Delve into the challenges and considerations of implementing Observers, examining various approaches and their trade-offs in real-world scenarios. Learn about subscription models, deregistration, prioritization, and thread-safety concerns. Discover how to leverage borrowed techniques from other languages in a value-oriented context, and gain insights into creating uniform code structures while avoiding blind adherence to design patterns. Benefit from the speaker's 20 years of professional C++ experience as he shares practical implementations and optimization techniques for modern C++ development.

Introduction
Background
Spooky Action at the Distance
entangled particles
uniform code structure
Presentation
What can we say
Observers are everywhere
Common vocabulary
Subscription model
Spooky action at a distance
A trivial example
Oversubscribing
Local Reasoning
Dependencies
Deregistration
Unsubscribe
Adding Observers
Priorities
Defining the API
Broadcast
Change
Deregister
Remove Observer
Zombie Slots
Cleanup
Recursive Observer
Actor Observer
M Observer
Intrusive Design
Lazy Vectors
Application Threads
deadlock
values
making copies
taking copies
delete later
Thread Safe Observer Pattern
Solid Observer Pattern
Intrusive Observer Pattern
not in the room
intotype