Deny defaults for higher-ranked generic parameters #119494
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fmease
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Jan 1, 2024
| @@ -62,6 +60,9 @@ ast_lowering_generic_type_with_parentheses = | |||
| parenthesized type parameters may only be used with a `Fn` trait | |||
| .label = only `Fn` traits may use parentheses | |||
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| ast_lowering_higher_ranked_gen_param_with_default = | |||
| higher-ranked generic parameters may not have defaults | |||
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Alternatively: defaults for {type|const|generic} parameters are not allowed in for<...> binders to mirror the diagnostic defaults for type parameters are only allowed in struct, enum, type, or trait definitions as well as some other diagnostics that use for<...> over higher-ranked.
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sure, i do like that alternative wording better
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fmease
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Jan 1, 2024
| @@ -884,27 +883,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { | |||
| binder: NodeId, | |||
| generic_params: &[GenericParam], | |||
| ) -> &'hir [hir::GenericParam<'hir>] { | |||
| let mut generic_params: Vec<_> = generic_params | |||
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Moving this into lower_generic_param_kind since lower_lifetime_binder doesn't get called on HRTBs.
fmease
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Jan 1, 2024
| | | ||
| LL | type T = dyn for<V = A(&())> Fn(()); | ||
| | ^ not found in this scope | ||
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| error: default parameter is not allowed in this binder | ||
| --> $DIR/issue-118697.rs:4:22 | ||
| error: higher-ranked generic parameters may not have defaults |
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I've updated the diagnostic message since I didn't find it clear and since we're now generally rejecting defaults for higher-ranked generic parameters.
compiler-errors
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Jan 1, 2024
| @@ -62,6 +60,9 @@ ast_lowering_generic_type_with_parentheses = | |||
| parenthesized type parameters may only be used with a `Fn` trait | |||
| .label = only `Fn` traits may use parentheses | |||
|
|
|||
| ast_lowering_higher_ranked_gen_param_with_default = | |||
| higher-ranked generic parameters may not have defaults | |||
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sure, i do like that alternative wording better
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thanks @fmease, I should've probably reviewed the other PR more carefully. r=me |
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Updated to use the alternative wording. |
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🌲 The tree is currently closed for pull requests below priority 100. This pull request will be tested once the tree is reopened. |
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…ompiler-errors Deny defaults for higher-ranked generic parameters Fixes rust-lang#119489 (incl. rust-lang#119489 (comment)). Partially reverts rust-lang#119042. cc `@bvanjoi` r? `@compiler-errors` or compiler
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…ompiler-errors Deny defaults for higher-ranked generic parameters Fixes rust-lang#119489 (incl. rust-lang#119489 (comment)). Partially reverts rust-lang#119042. cc ``@bvanjoi`` r? ``@compiler-errors`` or compiler
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Rollup of 21 pull requests Successful merges: - rust-lang#119086 (Query panic!() to useful diagnostic) - rust-lang#119239 (Remove unnecessary arm in `check_expr_yield`) - rust-lang#119298 (suppress change-tracker warnings in CI containers) - rust-lang#119319 (Document that File does not buffer reads/writes) - rust-lang#119434 (rc: Take *const T in is_dangling) - rust-lang#119444 (Rename `TyCtxt::is_closure` to `TyCtxt::is_closure_or_coroutine`) - rust-lang#119474 (Update tracking issue of naked_functions) - rust-lang#119476 (Pretty-print always-const trait predicates correctly) - rust-lang#119477 (rustdoc ui: adjust tooltip z-index to be above sidebar) - rust-lang#119479 (Remove two unused feature gates from rustc_query_impl) - rust-lang#119487 (Minor improvements in comment on `freshen.rs`) - rust-lang#119492 (Update books) - rust-lang#119494 (Deny defaults for higher-ranked generic parameters) - rust-lang#119498 (Update deadlinks of `strict_provenance` lints) - rust-lang#119505 (Don't synthesize host effect params for trait associated functions marked const) - rust-lang#119510 (Report I/O errors from rmeta encoding with emit_fatal) - rust-lang#119512 (Mark myself as back from leave) - rust-lang#119514 (coverage: Avoid a query stability hazard in `function_coverage_map`) - rust-lang#119523 (llvm: Allow `noundef` in codegen tests) - rust-lang#119534 (Update `thread_local` examples to use `local_key_cell_methods`) - rust-lang#119544 (Fix: Properly set vendor in i686-win7-windows-msvc target) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of rust-lang#119494 - fmease:deny-hr-param-defaults, r=compiler-errors Deny defaults for higher-ranked generic parameters Fixes rust-lang#119489 (incl. rust-lang#119489 (comment)). Partially reverts rust-lang#119042. cc ```@bvanjoi``` r? ```@compiler-errors``` or compiler
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Fixes #119489 (incl. #119489 (comment)).
Partially reverts #119042.
cc @bvanjoi
r? @compiler-errors or compiler