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@scottmcm scottmcm commented Feb 18, 2019

Inspired by seeing explicit lifetimes on these two:

And a follow-up to #54687, that started using IHLE in libcore.

Most of the changes in here fall into two big categories:

  • Removing lifetimes from common traits that can essentially never user a lifetime from an input (particularly Drop, Debug, and Clone)

  • Forwarding impls that are only possible because the lifetime doesn't matter (like impl<R: Read + ?Sized> Read for &mut R)

I omitted things that seemed like they could be more controversial, like the handful of iterators that have a Item: 'static despite the iterator having a lifetime or the PartialEq implementations where the flipped one cannot elide the lifetime.

I also removed two lifetimes that turned out to be completely unused; see #41960 (comment)

There are two big categories of changes in here

- Removing lifetimes from common traits that can essentially never user a lifetime from an input (particularly `Drop` & `Debug`)
- Forwarding impls that are only possible because the lifetime doesn't matter (like `impl<R: Read + ?Sized> Read for &mut R`)

I omitted things that seemed like they could be more controversial, like the handful of iterators that have a `Item: 'static` despite the iterator having a lifetime or the `PartialEq` implementations where the flipped one cannot elide the lifetime.
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@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 18, 2019
@scottmcm scottmcm added the T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. label Feb 18, 2019
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Centril commented Feb 18, 2019

Looks great. I love how clean things get!

r? @Centril

@bors r+

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bors commented Feb 18, 2019

📌 Commit 3bea2ca has been approved by Centril

@rust-highfive rust-highfive assigned Centril and unassigned aidanhs Feb 18, 2019
@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 18, 2019
kennytm added a commit to kennytm/rust that referenced this pull request Feb 20, 2019
Use more impl header lifetime elision

Inspired by seeing explicit lifetimes on these two:

- https://doc.rust-lang.org/nightly/std/slice/struct.Iter.html#impl-FusedIterator
- https://doc.rust-lang.org/nightly/std/primitive.u32.html#impl-Not

And a follow-up to rust-lang#54687, that started using IHLE in libcore.

Most of the changes in here fall into two big categories:

- Removing lifetimes from common traits that can essentially never user a lifetime from an input (particularly `Drop`, `Debug`, and `Clone`)

- Forwarding impls that are only possible because the lifetime doesn't matter (like `impl<R: Read + ?Sized> Read for &mut R`)

I omitted things that seemed like they could be more controversial, like the handful of iterators that have a `Item: 'static` despite the iterator having a lifetime or the `PartialEq` implementations [where the flipped one cannot elide the lifetime](https://internals.rust-lang.org/t/impl-type-parameter-aliases/9403/2?u=scottmcm).

I also removed two lifetimes that turned out to be completely unused; see rust-lang#41960 (comment)
bors added a commit that referenced this pull request Feb 20, 2019
Rollup of 24 pull requests

Successful merges:

 - #56470 (Modify doctest's auto-`fn main()` to allow `Result`s)
 - #58044 (Make overflowing and wrapping negation const)
 - #58303 (Improve stability tags display)
 - #58336 (Fix search results interactions)
 - #58384 (Fix tables display)
 - #58392 (Use less explicit shifting in std::net::ip)
 - #58409 (rustdoc: respect alternate flag when formatting impl trait)
 - #58456 (Remove no longer accurate diagnostic code about NLL)
 - #58528 (Don't use an allocation for ItemId in StmtKind)
 - #58530 (Monomorphize less code in fs::{read|write})
 - #58534 (Mention capping forbid lints)
 - #58536 (Remove UB in pointer tests)
 - #58538 (Add missing fmt structs examples)
 - #58539 (Add alias methods to PathBuf for underlying OsString (#58234))
 - #58544 (Fix doc for rustc "-g" flag)
 - #58545 (Add regression test for a specialization-related ICE (#39448))
 - #58546 (librustc_codegen_llvm => 2018)
 - #58551 (Explain a panic in test case net::tcp::tests::double_bind)
 - #58553 (Use more impl header lifetime elision)
 - #58562 (Fix style nits)
 - #58565 (Fix typo in std::future::Future docs)
 - #58568 (Fix a transposition in driver.rs.)
 - #58569 (Reduce Some Code Repetitions like `(n << amt) >> amt`)
 - #58576 (Stabilize iter::successors and iter::from_fn)
bors added a commit that referenced this pull request Feb 20, 2019
Rollup of 24 pull requests

Successful merges:

 - #56470 (Modify doctest's auto-`fn main()` to allow `Result`s)
 - #58044 (Make overflowing and wrapping negation const)
 - #58303 (Improve stability tags display)
 - #58336 (Fix search results interactions)
 - #58384 (Fix tables display)
 - #58392 (Use less explicit shifting in std::net::ip)
 - #58409 (rustdoc: respect alternate flag when formatting impl trait)
 - #58456 (Remove no longer accurate diagnostic code about NLL)
 - #58528 (Don't use an allocation for ItemId in StmtKind)
 - #58530 (Monomorphize less code in fs::{read|write})
 - #58534 (Mention capping forbid lints)
 - #58536 (Remove UB in pointer tests)
 - #58538 (Add missing fmt structs examples)
 - #58539 (Add alias methods to PathBuf for underlying OsString (#58234))
 - #58544 (Fix doc for rustc "-g" flag)
 - #58545 (Add regression test for a specialization-related ICE (#39448))
 - #58546 (librustc_codegen_llvm => 2018)
 - #58551 (Explain a panic in test case net::tcp::tests::double_bind)
 - #58553 (Use more impl header lifetime elision)
 - #58562 (Fix style nits)
 - #58565 (Fix typo in std::future::Future docs)
 - #58568 (Fix a transposition in driver.rs.)
 - #58569 (Reduce Some Code Repetitions like `(n << amt) >> amt`)
 - #58576 (Stabilize iter::successors and iter::from_fn)
@bors bors merged commit 3bea2ca into rust-lang:master Feb 20, 2019
@scottmcm scottmcm deleted the more-ihle branch February 21, 2019 08:19
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5 participants