a model of MIR and the Rust type/trait system
C-Rank Grade: A (Welcoming) - 62/100
External PR Merge Rate: 85%
Response Time: 4d
First Timer Success: 81%
rust-lang/a-mir-formality has a recorded first-timer success rate of 81.3%. Repositories ranked A typically provide actionable feedback during code reviews and actively nurture new community contributors.
Maintainers in rust-lang/a-mir-formality respond to incoming external pull requests in approximately 99.2 hours on average. Keeping PRs focused on single tasks and ensuring tests pass helps maintainers review faster.
The C-Rank™ system evaluates GitHub projects on a 0–100 scale using real data: PR merge rates, review turnaround time, active maintainer presence, and first-time contributor success. A score of 61.7 places rust-lang/a-mir-formality in the A tier.
The external contributor pull request merge rate for rust-lang/a-mir-formality is 85.0%, based on public PR activity from non-core contributors.
rust-lang/a-mir-formality currently has 3 active issue(s) tagged with beginner-friendly labels like "good first issue", "beginner", or "up-for-grabs".
Average Response Latency
Tracks hours until a maintainer leaves a review, comment, or PR response.
External Acceptance Rate
Percentage of community pull requests successfully merged into main.
First PR Conversion
Rate at which developers submitting their first repository PR succeed.
Show contributors that your repository actively reviews and merges external pull requests.
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We should make sure we throw an error for the test below. The function signature says u32 should be returned, but nothing is returned in the function body. #[test] fn i_am_a_test_that_should_be_renamed_later() { FormalityTest::new(crates![crate Foo { fn foo() -> u32 { } }]) .ok() }
Parent tracking issue: #288 Convert check_neg_trait_impl from a regular Rust function to a judgment function. Currently it: opens the binder, proves WF + not_implemented, and validates that negative impls are not declared unsafe. See the parent tracking issue for context and examples. This issue has been assigned to @Mslady-jojo via this comment.
Follow-up cleanup from PR #246: TypedPlaceExpression struct literal construction in nll.rs requires explicit Arc::new and .clone() calls: root: Arc::new(root_expr.clone()), ty: ty.clone(), kind: TypedPlaceExpressionKind::Deref(Arc::new(inner_expr.clone())), Upcast doesn't help with struct fields, so a constructor or builder that accepts impl Upcast<T> would be needed to clean this up. See: #246 (comment)
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When evaluating whether to contribute to rust-lang/a-mir-formality, response velocity and maintainer engagement are crucial. GetMerged continuously tracks pull request trajectories, first-comment latency, and code review rounds to help developers avoid submitting pull requests to backlogged repositories.
Currently, maintainers of rust-lang/a-mir-formality acknowledge new external contributions in approximately 4 days+. Out of all submitted pull requests from non-core authors in the last 180-day window, 85.0% were successfully merged into the primary branch.
rust-lang/a-mir-formality has a recorded first-timer success rate of 81.3%. Repositories ranked Welcoming typically provide actionable feedback during code reviews and actively nurture new community contributors.
The initial maintainer response time averages ~4 days+. Keeping PRs scoped to single concerns and ensuring CI checks succeed will optimize review turnaround.
The C-Rank™ index scores repositories on a 0 to 100 scale using an objective formula: external PR merge rates, initial response speed, active maintainer count, and first-time contributor retention. A score of 61.7 places rust-lang/a-mir-formality in the Welcoming tier.
The external pull request merge rate is 85.0%. GetMerged isolates non-core community contributions so external developers get an accurate benchmark of PR acceptance probability.
Yes, rust-lang/a-mir-formality currently has 3 active issue(s) tagged with beginner-friendly labels. You can inspect these directly from the repository issues tab.
All metrics displayed for rust-lang/a-mir-formality are automatically retrieved via the public GitHub API and recalculated daily. Insider pull requests submitted by repository owners or organization members are excluded from merge rate calculations to preserve objective external contributor statistics.