Main documentation

• cppreference.com: Coroutines

C++ Standard

• p.128: Await [expr.await]
• p.145: Yielding a value [expr.yield]
• p.161: The co_return statement [stmt.return.coroutine]
• p.217: Coroutine definitions [dcl.fct.def.coroutine]
• p.546: Coroutines (standard library) [support.coroutine]

Symmetric transfer of control

• Blog post: Lewis Baker ─ C++ Coroutines: Understanding Symmetric Transfer
• Proposal: P0913R0: Add symmetric coroutine control transfer

Halo: coroutine Heap Allocation eLision Optimization: the joint response

• Proposal: P0981R0: Halo: coroutine Heap Allocation eLision Optimization: the joint response

‍We DO NOT need to inline the body of the coroutine or the algorithm accumulate, unless the iterator type retains a pointer or reference to the generator<int> object.

Note that authors of coroutine types should be aware of this point: at least one blogger has described an implementation of generator<T>::iterator that holds a generator<T>*. However, every implementation of generator<T> we can find in the wild holds a coroutine_handle<Promise> instead, which avoids the problem, and allows heap allocation elision without inlining accumulate.