TyCtxt::variances_of is misdocumented as applying to a generic parameter #133494
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A-docs
Area: Documentation for any part of the project, including the compiler, standard library, and tools
A-variance
Area: Variance (https://doc.rust-lang.org/nomicon/subtyping.html)
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btj
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Good catch, feel free to submit a patch! Small correction: ... of the *item given by the |
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Rollup merge of rust-lang#134787 - fmease:spruce-up-queries, r=compiler-errors Spruce up the docs of several queries related to the type/trait system and const eval - Editorial - Proper rustdoc summary/synopsis line by making use of extra paragraphs: Leads to better rendered output on module pages, in search result lists and overall, too - Use rustdoc warning blocks for admonitions of the form "do not call / avoid calling this query directly" - Use intra-doc links of the form ``[`Self::$query`]`` to cross-link queries. Indeed, such links are generally a bit brittle due to the existence of `TyCtxtFeed` which only contains a subset of queries. Therefore the docs of `feedable` queries cannot cross-link to non-`feedable` ones. I'd say it's fine to use intra-doc links despite the potential/unlikely occasional future breakage (if a query with the aforementioned characteristics becomes `feedable`). `Self::` is nicer than `TyCtxt::` (which would be more stable) since it accounts for other contexts like `TyCtxt{Feed,At,Ensure{,WithValue}}` - Informative - Generally add, flesh out and correct some doc comments - Add *Panic* sections (to a few selected queries only). The lists of panics aren't necessarily exhaustive and focus on the more "obvious" or "important" panics. - Where applicable add a paragraph calling attention to the relevant [`#[rustc_*]` TEST attribute](https://rustc-dev-guide.rust-lang.org/compiler-debugging.html#rustc_-test-attributes) The one non-doc change (it's internal and not observable): Be even more defensive in `query constness`'s impl (spiritual follow-up to rust-lang#134122) (see self review comment). Fixes rust-lang#133494. r\? **any**(compiler-errors, oli-obk)
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…er-errors
Spruce up the docs of several queries related to the type/trait system and const eval
- Editorial
- Proper rustdoc summary/synopsis line by making use of extra paragraphs: Leads to better rendered output on module pages, in search result lists and overall, too
- Use rustdoc warning blocks for admonitions of the form "do not call / avoid calling this query directly"
- Use intra-doc links of the form ``[`Self::$query`]`` to cross-link queries. Indeed, such links are generally a bit brittle due to the existence of `TyCtxtFeed` which only contains a subset of queries. Therefore the docs of `feedable` queries cannot cross-link to non-`feedable` ones. I'd say it's fine to use intra-doc links despite the potential/unlikely occasional future breakage (if a query with the aforementioned characteristics becomes `feedable`). `Self::` is nicer than `TyCtxt::` (which would be more stable) since it accounts for other contexts like `TyCtxt{Feed,At,Ensure{,WithValue}}`
- Informative
- Generally add, flesh out and correct some doc comments
- Add *Panic* sections (to a few selected queries only). The lists of panics aren't necessarily exhaustive and focus on the more "obvious" or "important" panics.
- Where applicable add a paragraph calling attention to the relevant [`#[rustc_*]` TEST attribute](https://rustc-dev-guide.rust-lang.org/compiler-debugging.html#rustc_-test-attributes)
The one non-doc change (it's internal and not observable):
Be even more defensive in `query constness`'s impl (spiritual follow-up to rust-lang#134122) (see self review comment).
Fixes rust-lang#133494.
r\? **any**(compiler-errors, oli-obk)
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Location
https://doc.rust-lang.org/beta/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.variances_of
Summary
This method returns the variances of the generic parameters of the struct with the given def_id. Contrary to what the documentation suggests, when given the def_id of a generic parameter of a struct, it returns an empty slice.
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