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A comment on Rust – A hard decision pays off. Parent comment

Re:Rust – A hard decision pays off by Alexendoo on Wednesday August 24, 2022 @02:55PM (#32584077)
TrustedLen will mean it can safely take the upper bound, but Vec for example will still use the lower bound of the hint when something isn't TrustedLen

https://doc.rust-lang.org/src/alloc/vec/spec_from_iter_neste...

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Re:Rust – A hard decision pays off by tialaramex on Wednesday August 24, 2022 @03:14PM (#32584353)
Ooh nice, I hadn't seen that. OK, so there are probably places where I assumed the iterator won't do as nice a job of collect() as I did manually but I was wrong.

I wonder how the hell I didn't see that when I was tracking down how collect() ends up caring about TrustedLen.

Thanks.

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