Fibers: An Elegant Windows API

That documentation uses the clunky Windows API typedefs still burdened with its 16-bit heritage — e.g. being a “long pointer” from the segmented memory of the 8086:

Fibers are represented using opaque, void pointers. As I said, when any fiber returns from its start routine, it’s like returning from the main function, so it should probably have returned an integer. Windows fibers are a coroutine primitive suitable for async/await in C programs, where it can also be useful.

Source: nullprogram.com