Imagine a comparison function that needs to call sort() as part of its implementation. You could argue that's probably a bad idea, but it would be a problem for this case.
(You could solve that with a manually maintained stack for the context in a thread local, but you'd have to do that case-by-case)
Anyway, the larger point is that a re-entrant general solution is desirable. The sort example might be a bit misguided, because who calls sort-inside-sort[0]? Nobody, realistically, but these types of issues are prevalent in the "how to do closures" area... and In C every API does it slightly differently, even if they're even aware of the issues.
[0] Because there's no community that likes nitpicking like the C (or C++) community. I considered preempting that objection :). C++ has solved this, so there's that.
Imagine a comparison function that needs to call sort() as part of its implementation. You could argue that's probably a bad idea, but it would be a problem for this case.
(You could solve that with a manually maintained stack for the context in a thread local, but you'd have to do that case-by-case)
That is true. It can be protected against with assert.
I think the times you need to do this are few. And this version is much more pruden.
Assert what, exactly?
Anyway, the larger point is that a re-entrant general solution is desirable. The sort example might be a bit misguided, because who calls sort-inside-sort[0]? Nobody, realistically, but these types of issues are prevalent in the "how to do closures" area... and In C every API does it slightly differently, even if they're even aware of the issues.
[0] Because there's no community that likes nitpicking like the C (or C++) community. I considered preempting that objection :). C++ has solved this, so there's that.
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