24 lines
530 B
Rust
24 lines
530 B
Rust
#![warn(clippy::copy_iterator)]
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#[derive(Copy, Clone)]
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struct Countdown(u8);
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impl Iterator for Countdown {
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//~^ ERROR: you are implementing `Iterator` on a `Copy` type
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//~| NOTE: consider implementing `IntoIterator` instead
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type Item = u8;
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fn next(&mut self) -> Option<u8> {
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self.0.checked_sub(1).map(|c| {
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self.0 = c;
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c
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})
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}
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}
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fn main() {
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let my_iterator = Countdown(5);
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assert_eq!(my_iterator.take(1).count(), 1);
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assert_eq!(my_iterator.count(), 5);
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}
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