7eef946fc0
Implement `std::marker::Tuple`, use it in `extern "rust-call"` and `Fn`-family traits Implements rust-lang/compiler-team#537 I made a few opinionated decisions in this implementation, specifically: 1. Enforcing `extern "rust-call"` on fn items during wfcheck, 2. Enforcing this for all functions (not just ones that have bodies), 3. Gating this `Tuple` marker trait behind its own feature, instead of grouping it into (e.g.) `unboxed_closures`. Still needing to be done: 1. Enforce that `extern "rust-call"` `fn`-ptrs are well-formed only if they have 1/2 args and the second one implements `Tuple`. (Doing this would fix ICE in #66696.) 2. Deny all explicit/user `impl`s of the `Tuple` trait, kinda like `Sized`. 3. Fixing `Tuple` trait built-in impl for chalk, so that chalkification tests are un-broken. Open questions: 1. Does this need t-lang or t-libs signoff? Fixes #99820 |
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| Cargo.toml | ||
| README.md | ||
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.