C++20 Coroutines

Purpose

Guide agents through C++20 coroutine mechanics: co_await, co_yield, co_return, implementing the required promise_type, understanding coroutine frame memory layout, debugging suspended coroutines in GDB, and reducing frame allocation overhead.

Triggers

• "How do co_await, co_yield, and co_return work?"
• "How do I implement promise_type for a coroutine?"
• "How does a coroutine suspend and resume?"
• "How do I debug a suspended coroutine in GDB?"
• "How much memory does a coroutine frame use?"
• "How do I write a generator with co_yield?"

Workflow

1. The three coroutine keywords