Ushering out strlcpy()

Posted Aug 26, 2022 22:00 UTC (Fri) by NYKevin (subscriber, #129325)
In reply to: Ushering out strlcpy() by wtarreau
Parent article: Ushering out strlcpy()

Well, sure, but you wouldn't write that loop (in Rust) in the first place. You'd call str::find[1] with suitable arguments, and then it's the implementation's problem to emit the most efficient way to do this. Since one possible set of arguments to str::find can be statically proven to be exactly equivalent to strchr (purely in terms of the type system, so this can be done in the monomorphization pass), the implementation should emit strchr if it is optimal to do so. If the implementation does not in fact emit strchr, and you think this is suboptimal, then you should file a bug with them. But don't tell me it's impossible. It's clearly possible.

[1]: https://doc.rust-lang.org/std/primitive.str.html#method.find

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Ushering out strlcpy()

Posted Aug 29, 2022 9:37 UTC (Mon) by wtarreau (subscriber, #51152) [Link]

To be honest, I think you lost me, especially since initially I understood that it had to be handled as an array of bytes and not a string, but that sort of comforts me in the idea that it can quickly become very complicated to write simple yet efficient functions for a number of low-level use cases. And my fear with languages that are complicated to use is that either the developer will introduce logic bugs when trying to hack around constraints, or that they will give up and fall back to the default, much less efficient solution (which is often what we see in practice).