dcd643a652
`iter.last()` will drop all elements of `iter` in order, while `iter.next_back()` will drop the non-last elements of `iter` when `iter` goes out of scope since `.next_back()` does not consume its argument. When the transformation proposed by `double_ended_iterator_last` would concern an iterator whose element type has a significant drop, a note is added to warn about the possible drop order change, and the suggestion is switched from `MachineApplicable` to `MaybeIncorrect`.
23 lines
687 B
Rust
23 lines
687 B
Rust
//@no-rustfix
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#![warn(clippy::double_ended_iterator_last)]
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fn main() {
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let mut index = [true, true, false, false, false, true].iter();
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let subindex = (index.by_ref().take(3), 42);
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let _ = subindex.0.last(); //~ ERROR: called `Iterator::last` on a `DoubleEndedIterator`
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}
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fn drop_order() {
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struct S(&'static str);
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impl std::ops::Drop for S {
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fn drop(&mut self) {
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println!("Dropping {}", self.0);
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}
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}
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let v = vec![S("one"), S("two"), S("three")];
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let v = (v.into_iter(), 42);
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println!("Last element is {}", v.0.last().unwrap().0);
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//~^ ERROR: called `Iterator::last` on a `DoubleEndedIterator`
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println!("Done");
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}
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