[sempron64]

What I find interesting about coroutines is that they are relatively trivially achieved in hand-coded assembly using `jmp` and being careful about registers in a way that makes sense. `jmp`ing around is a pretty normal way to code in assembly. In a sophisticated environment they become a beast. It surprises me that we actually do lose something meaningful when abstracting to higher level languages.

[gnulinux]

Of course we lose something when we abstract to higher level languages, that's exactly what it means to abstract out. It'd be more surprising other way around. For example, when you're programming in a language like Haskell, Python or Java you cannot micromanage your pointers etc. This is because these languages abstract away the memory layout of objects. If you do hacky things and override the memory intentionally you can cause e.g. garbage collection to misbehave etc. On the other hand in C++ or C you can manage exactly how objects are encoded in the memory, when and how you allocate memory for your system. All these things are not things you're meant to be able to "customize" in higher level languages.