Added an additional example of lifetime elision #1678
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The question of how did this behave showed up in a rust-for-linux code review, and it would have been easier to explain had this example been present.
frewsxcv
approved these changes
Nov 19, 2024
|
We can verify these lifetimes are not equal with: fn lt_eq<'a: 'a, T>(_: &'a T) {}
fn f<'a>(x: &()) -> &'a () {
lt_eq::<'a>(x);
//~^ ERROR explicit lifetime required in the type of `x`
loop {}
}The error message there is somewhat less than optimal, as the problem isn't that the lifetime isn't named, but instead that the anonymous lifetime doesn't outlive fn lt_eq<'a: 'a, T>(_: &'a T) {}
fn f<'a, 'b>(x: &'b ()) -> &'a () {
lt_eq::<'a>(x);
//~^ ERROR lifetime may not live long enough
loop {}
}Regardless, this change to the Reference looks good. Thanks for the PR. |
traviscross
approved these changes
Nov 19, 2024
|
Thanks for the quick merge! |
bors
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Nov 25, 2024
Update cargo and books 10 commits in 66221abdeca2002d318fde6efff516aab091df0e..4c39aaff66862cc0da52fe529aa1990bb8bb9a22 2024-11-19 21:30:02 +0000 to 2024-11-25 16:36:17 +0000 - feat: Stabilize Edition 2024 (rust-lang/cargo#14828) - Improve error handling when PathSource is relative (rust-lang/cargo#14854) - test: address test output nondeterminism (rust-lang/cargo#14855) - chore: move supports-unicode to workspace deps (rust-lang/cargo#14853) - Check build target supports std when building with -Zbuild-std=std (rust-lang/cargo#14183) - fix(publish): Allow dry-run of a non-bumped workspace (rust-lang/cargo#14847) - test: Switch from 'exec_with_output' to 'run' (rust-lang/cargo#14848) - test(rustflags): Verify -Cmetadata directly, not through -Cextra-filename (rust-lang/cargo#14846) - chore: remove bors mentions (rust-lang/cargo#14845) - Clarify how `cargo::metadata` env var is selected (rust-lang/cargo#14842) ## nomicon 1 commits in eac89a3cbe6c4714e5029ae8b5a1c556fd4e8c42..0674321898cd454764ab69702819d39a919afd68 2024-11-16 14:05:28 +0000 to 2024-11-19 12:35:48 +0000 - races: Clarify a “mostly” that might be misread (rust-lang/nomicon#468) ## reference 12 commits in 41ccb0e6478305401dad92e8fd3d04a4304edb4c..5c86c739ec71b8bc839310ff47fa94e94635bba9 2024-11-15 21:45:16 +0000 to 2024-11-25 17:23:35 +0000 - Document `gen` keyword as reserved in Rust 2024 (rust-lang/reference#1501) - 2024: Update `expr` macro fragment specifier (rust-lang/reference#1639) - Add rust_2024 prelude (rust-lang/reference#1552) - 2024: Add reserved syntax (rust-lang/reference#1652) - Add Lifetime Capture Rules 2024 (rust-lang/reference#1601) - Add a section dedicated to Edition 2024 changes to temporary scopes (rust-lang/reference#1592) - 2024: Add unsafe attribute differences (rust-lang/reference#1579) - 2024: Add updates for unsafe extern blocks (rust-lang/reference#1565) - Fix rule for lazy boolean temporary drop scope (rust-lang/reference#1681) - Raw lifetimes (rust-lang/reference#1603) - Fix some missing emdashes (rust-lang/reference#1676) - Added an additional example of lifetime elision (rust-lang/reference#1678) ## rustc-dev-guide 6 commits in b679e71..787b416 2024-11-18 16:18:15 +0800 to 2024-11-22 11:17:57 +0000 - Remove constants section as it is outdated - Flatten generic parameter defs section - Add instructions to test error code docs (rust-lang/rustc-dev-guide#2145) - Reorganize the "Source Code Representation" chapters (rust-lang/rustc-dev-guide#2142) - Make `Diag` a clickable link in Suggestion section (rust-lang/rustc-dev-guide#2140) - update for rustc_intrinsic_const_stable_indirect (rust-lang/rustc-dev-guide#2138) ## edition-guide 6 commits in 915f9b319c2823f310430ecdecd86264a7870d7e..f48b0e842a3911c63240e955d042089e9e0894c7 2024-11-06 07:23:07 +0000 to 2024-11-25 16:20:27 +0000 - Update for 2024 stabilization (rust-lang/edition-guide#338) - Enable triagebot merge-conflicts and shortcuts (rust-lang/edition-guide#336) - Organize the 2024 chapters into sub-chapters by category (rust-lang/edition-guide#334) - Fix broken Cargo Book link in cargo-resolver.md (rust-lang/edition-guide#335) - Edition 2024 guide for temporary lifetime changes (rust-lang/edition-guide#318) - 2024: rustfmt sorting (rust-lang/edition-guide#332)
bors
added a commit
to rust-lang-ci/rust
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Nov 26, 2024
Update cargo and books 10 commits in 66221abdeca2002d318fde6efff516aab091df0e..4c39aaff66862cc0da52fe529aa1990bb8bb9a22 2024-11-19 21:30:02 +0000 to 2024-11-25 16:36:17 +0000 - feat: Stabilize Edition 2024 (rust-lang/cargo#14828) - Improve error handling when PathSource is relative (rust-lang/cargo#14854) - test: address test output nondeterminism (rust-lang/cargo#14855) - chore: move supports-unicode to workspace deps (rust-lang/cargo#14853) - Check build target supports std when building with -Zbuild-std=std (rust-lang/cargo#14183) - fix(publish): Allow dry-run of a non-bumped workspace (rust-lang/cargo#14847) - test: Switch from 'exec_with_output' to 'run' (rust-lang/cargo#14848) - test(rustflags): Verify -Cmetadata directly, not through -Cextra-filename (rust-lang/cargo#14846) - chore: remove bors mentions (rust-lang/cargo#14845) - Clarify how `cargo::metadata` env var is selected (rust-lang/cargo#14842) ## nomicon 1 commits in eac89a3cbe6c4714e5029ae8b5a1c556fd4e8c42..0674321898cd454764ab69702819d39a919afd68 2024-11-16 14:05:28 +0000 to 2024-11-19 12:35:48 +0000 - races: Clarify a “mostly” that might be misread (rust-lang/nomicon#468) ## reference 12 commits in 41ccb0e6478305401dad92e8fd3d04a4304edb4c..5c86c739ec71b8bc839310ff47fa94e94635bba9 2024-11-15 21:45:16 +0000 to 2024-11-25 17:23:35 +0000 - Document `gen` keyword as reserved in Rust 2024 (rust-lang/reference#1501) - 2024: Update `expr` macro fragment specifier (rust-lang/reference#1639) - Add rust_2024 prelude (rust-lang/reference#1552) - 2024: Add reserved syntax (rust-lang/reference#1652) - Add Lifetime Capture Rules 2024 (rust-lang/reference#1601) - Add a section dedicated to Edition 2024 changes to temporary scopes (rust-lang/reference#1592) - 2024: Add unsafe attribute differences (rust-lang/reference#1579) - 2024: Add updates for unsafe extern blocks (rust-lang/reference#1565) - Fix rule for lazy boolean temporary drop scope (rust-lang/reference#1681) - Raw lifetimes (rust-lang/reference#1603) - Fix some missing emdashes (rust-lang/reference#1676) - Added an additional example of lifetime elision (rust-lang/reference#1678) ## rustc-dev-guide 6 commits in b679e71..787b416 2024-11-18 16:18:15 +0800 to 2024-11-22 11:17:57 +0000 - Remove constants section as it is outdated - Flatten generic parameter defs section - Add instructions to test error code docs (rust-lang/rustc-dev-guide#2145) - Reorganize the "Source Code Representation" chapters (rust-lang/rustc-dev-guide#2142) - Make `Diag` a clickable link in Suggestion section (rust-lang/rustc-dev-guide#2140) - update for rustc_intrinsic_const_stable_indirect (rust-lang/rustc-dev-guide#2138) ## edition-guide 6 commits in 915f9b319c2823f310430ecdecd86264a7870d7e..f48b0e842a3911c63240e955d042089e9e0894c7 2024-11-06 07:23:07 +0000 to 2024-11-25 16:20:27 +0000 - Update for 2024 stabilization (rust-lang/edition-guide#338) - Enable triagebot merge-conflicts and shortcuts (rust-lang/edition-guide#336) - Organize the 2024 chapters into sub-chapters by category (rust-lang/edition-guide#334) - Fix broken Cargo Book link in cargo-resolver.md (rust-lang/edition-guide#335) - Edition 2024 guide for temporary lifetime changes (rust-lang/edition-guide#318) - 2024: rustfmt sorting (rust-lang/edition-guide#332)
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The question of how did this behave showed up in a rust-for-linux code review, and it would have been easier to explain had this example been present.