Understanding C++ Coroutines by Example, Part 1
summary
Builds a minimal coroutine library from the ground up: a task + promise type, the five mandatory promise functions, get_return_object, initial/final_suspend behavior, and how co_await is lowered to awaitable checks and suspend/resume. Implements a task::operator co_await, a final awaitable that resumes a continuation, and a sync_wait using std::promise/std::future with atomic states to make it thread safe (atomic states: started/attached/finished). Demonstrates an async file read with worker thread, shows why detach can lose results, and recommends Lewis Baker’s cppcoro.
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chapters (14)
- 0:00Start
- 8:44Curtain Statement
- 11:16Initial Suspend
- 12:30Default Constructor
- 12:45Promise Pointer
- 14:40Get Return Objects
- 16:59Return Value
- 18:03Unhandled Exception
- 20:15Mandatory Member Functions
- 23:58Recap
- 27:16Operator Function Call
- 36:00Catch Clause
- 42:40Suspend
- 55:11Implementation
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