Clarify that 0 is a valid multiple of a type's alignment #1260
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The reference currently states that "[t]he size of a value is always a multiple of its alignment." This might be taken to imply that a type's size is greater than or equal to its alignment. This commit clarifies that 0 is a valid multiple; zero-sized types have 0 size and nonzero alignment.
ehuss
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Sep 10, 2022
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Thanks! Yea, it does seem like 0 is considered a factor. I've always felt this paragraph is a bit awkward in how it uses array layout to define size.
I'm going to go ahead and merge even though I'm not 100% confident in the wording here. If someone wants to rework it to be clearer, feel free to follow up.
matthiaskrgr
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Sep 21, 2022
Update books ## nomicon 1 commits in d880e6ac2acf133dce640da24b9fb692844f02d4..f53bfa056929217870a5d2df1366d2e7ba35096d 2022-08-24 12:42:34 -0700 to 2022-09-05 07:19:02 -0700 - Small typo (rust-lang/nomicon#379) ## reference 9 commits in f62e93c28323ed9637d0a205a0c256498674a509..a7cdac33ca7356ad49d5c2b5e2c5010889b33eee 2022-08-28 10:01:28 -0700 to 2022-09-19 17:39:58 -0700 - Clarify wording for references. (rust-lang/reference#1223) - Update Unicode reference to match rustc implementation (rust-lang/reference#1271) - Add documentation for raw-dylib and link_ordinal (rust-lang/reference#1244) - Specify guarantees for repr(rust) structs (rust-lang/reference#1152) - Classify AsyncBlockExpression as ExpressionWithoutBlock (rust-lang/reference#1268) - Update closure-expr.md (rust-lang/reference#1269) - Clarify that 0 is a valid multiple of a type's alignment (rust-lang/reference#1260) - Remove `ne` from derive example (rust-lang/reference#1264) - Clarify reference on async blocks (rust-lang/reference#1262) ## book 6 commits in 0a5421ceb238357b3634fb75234eba4d1dad643c..f1e5ad844d0c61738006cdef26227beeb136948e 2022-08-28 19:51:04 -0400 to 2022-09-19 09:48:21 -0400 - Fix punctuation in ch05-02 - Ownership move chapter link fix - Wrong listing number - Reword text around box - `Box<T>` instead of "box" - Update Clippy output in Appendix D ## rust-by-example 2 commits in 03301f8ae55fa6f20f7ea152a517598e6db2cdb7..767a6bd9727a596d7cfdbaeee475e65b2670ea3a 2022-08-14 08:51:44 -0300 to 2022-09-14 09:17:18 -0300 - struct_visibility.md: Remove unneeded '#[allow(dead_code)]' (rust-lang/rust-by-example#1609) - Fix assorted typos (rust-lang/rust-by-example#1601) ## rustc-dev-guide 15 commits in 04892c1a6fc145602ac7367945fda9d4ee83c9fb..f587d6e7cddeaa3cf0a33ec1e368df1a408fa0aa 2022-08-29 20:07:51 +0200 to 2022-09-20 07:43:59 +0900 - Update stability guide to use CURRENT_RUSTC_VERSION (rust-lang/rustc-dev-guide#1468) - Add a note about building `rust-analyzer-proc-macro-srv` (rust-lang/rustc-dev-guide#1467) - Link from "implementing to new features" to mcp.md (rust-lang/rustc-dev-guide#1465) - remove stray ** - Explain the new valtree system for type level constants. (rust-lang/rustc-dev-guide#1097) - fix typos and formatting - Say "bootstrap" instead of "rustbuild"; the latter is not explained anywhere and is not much more clear. - Rewrite the section on passing flags to subcommands - Remove the diagram of all outputs generated by x.py - "symbol names" => ABI - Add symbol-addition to the how-to for new features (rust-lang/rustc-dev-guide#1457) - Fix typo (rust-lang/rustc-dev-guide#1459) - Document multipart_suggestion derive on SessionSubdiagnostic - Add reference for updating Windows PATH and fix typo - Update for removal of RLS (rust-lang/rustc-dev-guide#1450) ## embedded-book 1 commits in befe6840874311635c417cf731377f07234ee373..4ce51cb7441a6f02b5bf9b07b2eb755c21ab7954 2022-07-25 07:51:14 +0000 to 2022-09-15 08:53:09 +0000 - Create CITATION.bib (as per rust-embedded/book#327) (rust-embedded/book#329)
JohnTitor
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Sep 22, 2022
Update books ## nomicon 1 commits in d880e6ac2acf133dce640da24b9fb692844f02d4..f53bfa056929217870a5d2df1366d2e7ba35096d 2022-08-24 12:42:34 -0700 to 2022-09-05 07:19:02 -0700 - Small typo (rust-lang/nomicon#379) ## reference 9 commits in f62e93c28323ed9637d0a205a0c256498674a509..a7cdac33ca7356ad49d5c2b5e2c5010889b33eee 2022-08-28 10:01:28 -0700 to 2022-09-19 17:39:58 -0700 - Clarify wording for references. (rust-lang/reference#1223) - Update Unicode reference to match rustc implementation (rust-lang/reference#1271) - Add documentation for raw-dylib and link_ordinal (rust-lang/reference#1244) - Specify guarantees for repr(rust) structs (rust-lang/reference#1152) - Classify AsyncBlockExpression as ExpressionWithoutBlock (rust-lang/reference#1268) - Update closure-expr.md (rust-lang/reference#1269) - Clarify that 0 is a valid multiple of a type's alignment (rust-lang/reference#1260) - Remove `ne` from derive example (rust-lang/reference#1264) - Clarify reference on async blocks (rust-lang/reference#1262) ## book 6 commits in 0a5421ceb238357b3634fb75234eba4d1dad643c..f1e5ad844d0c61738006cdef26227beeb136948e 2022-08-28 19:51:04 -0400 to 2022-09-19 09:48:21 -0400 - Fix punctuation in ch05-02 - Ownership move chapter link fix - Wrong listing number - Reword text around box - `Box<T>` instead of "box" - Update Clippy output in Appendix D ## rust-by-example 2 commits in 03301f8ae55fa6f20f7ea152a517598e6db2cdb7..767a6bd9727a596d7cfdbaeee475e65b2670ea3a 2022-08-14 08:51:44 -0300 to 2022-09-14 09:17:18 -0300 - struct_visibility.md: Remove unneeded '#[allow(dead_code)]' (rust-lang/rust-by-example#1609) - Fix assorted typos (rust-lang/rust-by-example#1601) ## rustc-dev-guide 15 commits in 04892c1a6fc145602ac7367945fda9d4ee83c9fb..f587d6e7cddeaa3cf0a33ec1e368df1a408fa0aa 2022-08-29 20:07:51 +0200 to 2022-09-20 07:43:59 +0900 - Update stability guide to use CURRENT_RUSTC_VERSION (rust-lang/rustc-dev-guide#1468) - Add a note about building `rust-analyzer-proc-macro-srv` (rust-lang/rustc-dev-guide#1467) - Link from "implementing to new features" to mcp.md (rust-lang/rustc-dev-guide#1465) - remove stray ** - Explain the new valtree system for type level constants. (rust-lang/rustc-dev-guide#1097) - fix typos and formatting - Say "bootstrap" instead of "rustbuild"; the latter is not explained anywhere and is not much more clear. - Rewrite the section on passing flags to subcommands - Remove the diagram of all outputs generated by x.py - "symbol names" => ABI - Add symbol-addition to the how-to for new features (rust-lang/rustc-dev-guide#1457) - Fix typo (rust-lang/rustc-dev-guide#1459) - Document multipart_suggestion derive on SessionSubdiagnostic - Add reference for updating Windows PATH and fix typo - Update for removal of RLS (rust-lang/rustc-dev-guide#1450) ## embedded-book 1 commits in befe6840874311635c417cf731377f07234ee373..4ce51cb7441a6f02b5bf9b07b2eb755c21ab7954 2022-07-25 07:51:14 +0000 to 2022-09-15 08:53:09 +0000 - Create CITATION.bib (as per rust-embedded/book#327) (rust-embedded/book#329)
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The reference currently states that "[t]he size of a value is always a multiple of its alignment." This might be taken to imply that a type's size is greater than or equal to its alignment. This commit clarifies that 0 is a valid multiple; zero-sized types have 0 size and nonzero alignment.