I don't have that much experience with Rust, but all modern C++ compilers would have no problem inlining a similar abstraction at compile time. Remember that th

I don't have that much experience with Rust, but all modern C++ compilers would have no problem inlining a similar abstraction at compile time. Remember that they're turning the whole future chaining into a switch statement inside of a function that is re-entered until a completion state is reached. Ala async/await in C#.