do not unnecessarily leak auto traits in item bounds #139789
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| //@ revisions: current next | |||
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I think this should be marked as a known-bug.
| // To avoid this we don't try to leak auto trait bounds if they can also be proven via | ||
| // item bounds of the opaque. These bounds are always applicable as auto traits must not | ||
| // have any generic parameters. They would also get preferred over the impl candidate | ||
| // when merging candidates anyways. |
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Maybe find some place to also explicitly mention that this is sound b/c we later separately check that the hidden type implements the RPIT's bounds after opaque type inference.
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this feels like a more general question about alias bound candidates of opaques 🤔 so we'd probably have to put it there. To be totally honest, I am not confident that it is fully sound in the first place as long as checking well-formedness for opaque types happens in analysis mode xx
I've kept #109387 in my github notifications for multiple months now
tests/ui/impl-trait/in-trait/method-compatability-via-leakage.stderr
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@bors r+ rollup |
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…=compiler-errors do not unnecessarily leak auto traits in item bounds fixes rust-lang/trait-system-refactor-initiative#158 Not a fix for rust-lang/trait-system-refactor-initiative#173 as you may have realized/tried yourself, cc rust-lang#139788. However, fixing this feels desirable regardless and I don't see any reason not to. r? `@compiler-errors`
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Rollup of 12 pull requests Successful merges: - rust-lang#138374 (Enable contracts for const functions) - rust-lang#138380 (ci: add runners for vanilla LLVM 20) - rust-lang#138393 (Allow const patterns of matches to contain pattern types) - rust-lang#139393 (rustdoc-json: Output target feature information) - rust-lang#139517 (std: sys: process: uefi: Use NULL stdin by default) - rust-lang#139554 (std: add Output::exit_ok) - rust-lang#139745 (Avoid unused clones in `Cloned<I>` and `Copied<I>`) - rust-lang#139757 (opt-dist: use executable-extension for host llvm-profdata) - rust-lang#139778 (Add test for issue 34834) - rust-lang#139783 (Use `compiletest-ignore-dir` for bootstrap self-tests) - rust-lang#139789 (do not unnecessarily leak auto traits in item bounds) - rust-lang#139791 (drop global where-bounds before merging candidates) r? `@ghost` `@rustbot` modify labels: rollup
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…=compiler-errors do not unnecessarily leak auto traits in item bounds fixes rust-lang/trait-system-refactor-initiative#158 Not a fix for rust-lang/trait-system-refactor-initiative#173 as you may have realized/tried yourself, cc rust-lang#139788. However, fixing this feels desirable regardless and I don't see any reason not to. r? ``@compiler-errors``
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Rollup of 17 pull requests Successful merges: - rust-lang#138374 (Enable contracts for const functions) - rust-lang#138380 (ci: add runners for vanilla LLVM 20) - rust-lang#138393 (Allow const patterns of matches to contain pattern types) - rust-lang#139517 (std: sys: process: uefi: Use NULL stdin by default) - rust-lang#139554 (std: add Output::exit_ok) - rust-lang#139660 (compiletest: Add an experimental new executor to replace libtest) - rust-lang#139669 (Overhaul `AssocItem`) - rust-lang#139671 (Proc macro span API redesign: Replace proc_macro::SourceFile by Span::{file, local_file}) - rust-lang#139750 (std/thread: Use default stack size from menuconfig for NuttX) - rust-lang#139772 (Remove `hir::Map`) - rust-lang#139785 (Let CStrings be either 1 or 2 byte aligned.) - rust-lang#139789 (do not unnecessarily leak auto traits in item bounds) - rust-lang#139791 (drop global where-bounds before merging candidates) - rust-lang#139798 (normalize: prefer `ParamEnv` over `AliasBound` candidates) - rust-lang#139822 (Fix: Map EOPNOTSUPP to ErrorKind::Unsupported on Unix) - rust-lang#139833 (Fix some HIR pretty-printing problems) - rust-lang#139836 (Basic tests of MPMC receiver cloning) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of rust-lang#139789 - lcnr:opaques-auto-trait-leakage, r=compiler-errors do not unnecessarily leak auto traits in item bounds fixes rust-lang/trait-system-refactor-initiative#158 Not a fix for rust-lang/trait-system-refactor-initiative#173 as you may have realized/tried yourself, cc rust-lang#139788. However, fixing this feels desirable regardless and I don't see any reason not to. r? ```@compiler-errors```
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Rollup of 17 pull requests Successful merges: - rust-lang#138374 (Enable contracts for const functions) - rust-lang#138380 (ci: add runners for vanilla LLVM 20) - rust-lang#138393 (Allow const patterns of matches to contain pattern types) - rust-lang#139517 (std: sys: process: uefi: Use NULL stdin by default) - rust-lang#139554 (std: add Output::exit_ok) - rust-lang#139660 (compiletest: Add an experimental new executor to replace libtest) - rust-lang#139669 (Overhaul `AssocItem`) - rust-lang#139671 (Proc macro span API redesign: Replace proc_macro::SourceFile by Span::{file, local_file}) - rust-lang#139750 (std/thread: Use default stack size from menuconfig for NuttX) - rust-lang#139772 (Remove `hir::Map`) - rust-lang#139785 (Let CStrings be either 1 or 2 byte aligned.) - rust-lang#139789 (do not unnecessarily leak auto traits in item bounds) - rust-lang#139791 (drop global where-bounds before merging candidates) - rust-lang#139798 (normalize: prefer `ParamEnv` over `AliasBound` candidates) - rust-lang#139822 (Fix: Map EOPNOTSUPP to ErrorKind::Unsupported on Unix) - rust-lang#139833 (Fix some HIR pretty-printing problems) - rust-lang#139836 (Basic tests of MPMC receiver cloning) r? `@ghost` `@rustbot` modify labels: rollup
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fixes rust-lang/trait-system-refactor-initiative#158
Not a fix for rust-lang/trait-system-refactor-initiative#173 as you may have realized/tried yourself, cc #139788. However, fixing this feels desirable regardless and I don't see any reason not to.
r? @compiler-errors