Add some documentation for unsizing #1817
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compiler-errors
commented
Nov 1, 2023
| * `Struct<.., T, ..>: Unsize<Struct<.., U, ..>> where T: Unsize<U>` allows the | ||
| tail field of a struct to be unsized. | ||
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| The rules for the latter implementation are slightly complicated, since they |
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I could go into more detail here -- specifically, uplift some of the clarifications from: rust-lang/rust#117495
lcnr
approved these changes
Nov 2, 2023
src/traits/unsize.md
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| structural: | ||
| * `(A1, A2, .., An): Unsize<(A1, A2, .., U)> where An: Unsize<U>` allows the | ||
| tail field of a tuple to be unsized. | ||
| * `Struct<.., T, ..>: Unsize<Struct<.., U, ..>> where T: Unsize<U>` allows the |
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looking at rust-lang/rust#117495 this explanation feels misleading, maybe
Struct<.., Pi, .., Pj, ..>: Unsize<Struct<.., Ui, .., Uj, ..>> where TailField<Pi, .., Pj>: Unsize<Ui, .., Uj>allows the tail field of a struct to be unsized.
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matthiaskrgr
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Nov 7, 2023
Update books ## rust-lang/reference 4 commits in 16fd3c06d9e558dae2d52000818274ae70c9e90a..cd8193e972f61b92117095fc73b67af767b4d6bc 2023-11-04 17:19:39 UTC to 2023-10-30 16:04:52 UTC - Guarantee that raw pointer conversions preserve slice element count (rust-lang/reference#1417) - some asm block flags also mean there can be no fences (rust-lang/reference#1413) - Guarantee `char` layout (rust-lang/reference#1401) - Doc: Add the RISC-V stabilized target features (rust-lang/reference#1415) ## rust-lang/rust-by-example 3 commits in 6709beeb7d0fbc5ffc91ac4893a24434123b9bfa..311b84962016b28c75525c86e7b3f49fd9101a39 2023-10-31 18:32:09 UTC to 2023-10-31 18:30:39 UTC - Fixed explanation mistake in comment (rust-lang/rust-by-example#1761) - Fix typos (rust-lang/rust-by-example#1759) - docs(9.2): fix typo (rust-lang/rust-by-example#1754) ## rust-lang/rustc-dev-guide 6 commits in b0ee9ec..77dbe57 2023-11-06 16:14:34 UTC to 2023-10-29 17:16:02 UTC - add a new type system invariant (rust-lang/rustc-dev-guide#1822) - Update some outdated descriptions of coverage instrumentation (rust-lang/rustc-dev-guide#1809) - Add some documentation for unsizing (rust-lang/rustc-dev-guide#1817) - Bibliography: fixing author of "You Can't Spell Trust Without Rust" (rust-lang/rustc-dev-guide#1815) - remove change-id from sample build configuration (rust-lang/rustc-dev-guide#1813) - Update name of "active" features to "unstable" (rust-lang/rustc-dev-guide#1814)
rust-timer
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Nov 7, 2023
Rollup merge of rust-lang#117639 - rustbot:docs-update, r=ehuss Update books ## rust-lang/reference 4 commits in 16fd3c06d9e558dae2d52000818274ae70c9e90a..cd8193e972f61b92117095fc73b67af767b4d6bc 2023-11-04 17:19:39 UTC to 2023-10-30 16:04:52 UTC - Guarantee that raw pointer conversions preserve slice element count (rust-lang/reference#1417) - some asm block flags also mean there can be no fences (rust-lang/reference#1413) - Guarantee `char` layout (rust-lang/reference#1401) - Doc: Add the RISC-V stabilized target features (rust-lang/reference#1415) ## rust-lang/rust-by-example 3 commits in 6709beeb7d0fbc5ffc91ac4893a24434123b9bfa..311b84962016b28c75525c86e7b3f49fd9101a39 2023-10-31 18:32:09 UTC to 2023-10-31 18:30:39 UTC - Fixed explanation mistake in comment (rust-lang/rust-by-example#1761) - Fix typos (rust-lang/rust-by-example#1759) - docs(9.2): fix typo (rust-lang/rust-by-example#1754) ## rust-lang/rustc-dev-guide 6 commits in b0ee9ec..77dbe57 2023-11-06 16:14:34 UTC to 2023-10-29 17:16:02 UTC - add a new type system invariant (rust-lang/rustc-dev-guide#1822) - Update some outdated descriptions of coverage instrumentation (rust-lang/rustc-dev-guide#1809) - Add some documentation for unsizing (rust-lang/rustc-dev-guide#1817) - Bibliography: fixing author of "You Can't Spell Trust Without Rust" (rust-lang/rustc-dev-guide#1815) - remove change-id from sample build configuration (rust-lang/rustc-dev-guide#1813) - Update name of "active" features to "unstable" (rust-lang/rustc-dev-guide#1814)
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Possibly satisfies rust-lang/rust#65991 (comment), though I really kinda want to know what needs to be specified here.
r? @lcnr