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Remove Clone requirement from unique#776

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gilhooleyd wants to merge 1 commit intorust-itertools:masterfrom
gilhooleyd:unique_no_clone
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Remove Clone requirement from unique#776
gilhooleyd wants to merge 1 commit intorust-itertools:masterfrom
gilhooleyd:unique_no_clone

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@gilhooleyd
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@gilhooleyd gilhooleyd commented Oct 6, 2023

This trait requirement appears to no longer be needed.

@gilhooleyd
Remove Clone requirement from unique
766a2d0 
This trait requirement appears to no longer be needed.
jswrenn
jswrenn previously approved these changes Oct 6, 2023
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@jswrenn jswrenn added this to the next milestone Oct 6, 2023
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Philippe-Cholet commented Oct 6, 2023

The item has to implement clone for Unique to be an iterator

@jswrenn jswrenn dismissed their stale review October 6, 2023 14:40

Iterating over a Unique still requires Clone.

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jswrenn commented Oct 6, 2023

@Philippe-Cholet's right. @gilhooleyd, could you submit a PR adding the Clone bound to the Unique definition:

itertools/src/unique_impl.rs

Lines 163 to 170 in 4d2bd4e

/// An iterator adapter to filter out duplicate elements.
///
/// See [`.unique()`](crate::Itertools::unique) for more information.
#[derive(Clone)]
#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
pub struct Unique<I: Iterator> {
iter: UniqueBy<I, I::Item, ()>,
}

@jswrenn jswrenn closed this Oct 6, 2023
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gilhooleyd commented Oct 6, 2023

Thanks for the quick feedback! I was surprised to see that cargo test passed with this change, but it looks like there's no test code that calls unique and then iterates over it. Adding that test and then trying to remove Clone further I see that the header comments are correct (Unique does clone each item to place it in the hashmap to look for duplicates).

I'll submit another PR to add a test and the trait

@gilhooleyd gilhooleyd mentioned this pull request Oct 6, 2023
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@gilhooleyd @Philippe-Cholet @jswrenn