Deciphering C++ Coroutines - A Diagrammatic Coroutine Cheat Sheet - Andreas Weis - CppCon 2022

Discover the intricacies of C++ coroutines with this comprehensive cheat sheet, covering topics like `await`, suspend points, promises, and customization options for advanced developers.

Key takeaways

C++ coroutines consist of the await keyword and the return statement.
Coroutines have three points for suspension: await_suspend, initial_suspend, and final_suspend.
When a coroutine is created, the return type becomes the coroutine’s result type.
When await_suspend is called, control flow returns to the caller, allowing them to store a handle to the coroutine.
When the promise is passed to getReturnObject, the await_suspend function is called.
Coroutines do not directly access their suspend points, they rely on their promise for suspension and cancellation.
Promises hold on to the result type, suspension points and destruction points of coroutines.
Initial suspend puts the coroutine to sleep.
Final suspend gets called when a coroutine returns and checks if there’s any unhandled exception.
Cancellation points determine when and if a coroutine’s execution will resume.
Co_yield acts like syntactic sugar, allows users to define what’s stored in the promise.
Coroutine Traits can be customized.
Initial Suspend and Final Suspend permit controlling what happens when a coroutine enters and leaves the suspension points.

Deciphering C++ Coroutines - A Diagrammatic Coroutine Cheat Sheet - Andreas Weis - CppCon 2022

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