Why doesn't `Range<T: Copy>` implement `Copy`?

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This has confused me before. std::ops::Range<T> is a struct containing two T. If it were annotated #[derive(Copy)], then for example, Range<usize> would be Copy. But for some reason it's not, and so when I store a Range in a struct that should be able to be Copy, it can't. I'm curious if there is some reason for this?

Edit: 2025 update, because this is still getting traffic

Rust RFC 3550 proposes fixing this issue by making ranges merely implement IntoIterator rather than Iterator, thus allowing them to implement Copy in a less complicated way. Per its tracking issue, it missed the cutoff for making it into Rust 2024 edition, but could potentially happen in Rust 2027 edition.

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Because it's an iterator, and iterators are generally not made Copy because that makes them do surprising things in for loops (and generally anything that "takes ownership").

There keep being conversations about splitting up the "interval from a to b" and "iterator from a to b" into different types (RangeInclusive is also a bit awkward here for the former use, because it's bigger than one would like for that use), but nothing's happened yet.

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