As historical note for those that don't follow C++, C++20 co-routines grew up from the work done with asynchronous programming on WinRT for C# and C++, inspired by Midori and .NET async/await.

Most of the magic methods expected by C++ compilers in awaitable types, are also present in the structured typing used by C# for awaitables.

The preview implementation for VC++ and clang were done by a Microsoft employee, Gor Nishanov, his talks are always quite interesting.