diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs index 02cfb57b836f..a7760326bb4c 100644 --- a/compiler/rustc_hir_analysis/src/variance/mod.rs +++ b/compiler/rustc_hir_analysis/src/variance/mod.rs @@ -27,9 +27,6 @@ mod solve; pub(crate) mod dump; -/// Code for transforming variances. -mod xform; - pub(crate) fn provide(providers: &mut Providers) { *providers = Providers { variances_of, crate_variances, ..*providers }; } diff --git a/compiler/rustc_hir_analysis/src/variance/solve.rs b/compiler/rustc_hir_analysis/src/variance/solve.rs index d0bdca867792..4106c1a5b635 100644 --- a/compiler/rustc_hir_analysis/src/variance/solve.rs +++ b/compiler/rustc_hir_analysis/src/variance/solve.rs @@ -12,8 +12,26 @@ use tracing::debug; use super::constraints::*; use super::terms::VarianceTerm::*; use super::terms::*; -use super::xform::*; +fn glb(v1: ty::Variance, v2: ty::Variance) -> ty::Variance { + // Greatest lower bound of the variance lattice as defined in The Paper: + // + // * + // - + + // o + match (v1, v2) { + (ty::Invariant, _) | (_, ty::Invariant) => ty::Invariant, + + (ty::Covariant, ty::Contravariant) => ty::Invariant, + (ty::Contravariant, ty::Covariant) => ty::Invariant, + + (ty::Covariant, ty::Covariant) => ty::Covariant, + + (ty::Contravariant, ty::Contravariant) => ty::Contravariant, + + (x, ty::Bivariant) | (ty::Bivariant, x) => x, + } +} struct SolveContext<'a, 'tcx> { terms_cx: TermsContext<'a, 'tcx>, constraints: Vec>, diff --git a/compiler/rustc_hir_analysis/src/variance/xform.rs b/compiler/rustc_hir_analysis/src/variance/xform.rs deleted file mode 100644 index 2e9964788e6e..000000000000 --- a/compiler/rustc_hir_analysis/src/variance/xform.rs +++ /dev/null @@ -1,22 +0,0 @@ -use rustc_middle::ty; - -pub(crate) fn glb(v1: ty::Variance, v2: ty::Variance) -> ty::Variance { - // Greatest lower bound of the variance lattice as - // defined in The Paper: - // - // * - // - + - // o - match (v1, v2) { - (ty::Invariant, _) | (_, ty::Invariant) => ty::Invariant, - - (ty::Covariant, ty::Contravariant) => ty::Invariant, - (ty::Contravariant, ty::Covariant) => ty::Invariant, - - (ty::Covariant, ty::Covariant) => ty::Covariant, - - (ty::Contravariant, ty::Contravariant) => ty::Contravariant, - - (x, ty::Bivariant) | (ty::Bivariant, x) => x, - } -}