[hallmark]

Are there useful heuristics on where GSL is most applicable? Where it is relevant and powerful and not too meta; just the right amount of abstraction to represent a problem and its solution.

For example, "GSL is likely a good choice at <abstract problem description>, such as <some very concrete examples>. And it may not be appropriate for <abstract problem description>, such as <other concrete examples>. Because of <some specific reasons>."

I looked through the GSL website and also Scalable C and wasn't able to find any descriptions that place limits on the applications of GSL. A description of what a complex something isn't, from an expert, is almost as important as what that thing is.

Your writing style in Scalable C is incredible and enlightening. I will be studying and referencing that book, even if I'm not directly coding C.