diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/misc.rs')
-rw-r--r-- | compiler/rustc_trait_selection/src/traits/misc.rs | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs index a41a601f2..b94346b09 100644 --- a/compiler/rustc_trait_selection/src/traits/misc.rs +++ b/compiler/rustc_trait_selection/src/traits/misc.rs @@ -1,12 +1,15 @@ //! Miscellaneous type-system utilities that are too small to deserve their own modules. -use crate::traits::{self, ObligationCause}; +use crate::traits::{self, ObligationCause, ObligationCtxt}; use rustc_data_structures::fx::FxIndexSet; use rustc_hir as hir; +use rustc_infer::infer::canonical::Canonical; use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt}; +use rustc_infer::traits::query::NoSolution; use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError}; -use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable}; +use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitableExt}; +use rustc_span::DUMMY_SP; use super::outlives_bounds::InferCtxtExt; @@ -131,3 +134,19 @@ pub fn type_allowed_to_implement_copy<'tcx>( Ok(()) } + +pub fn check_tys_might_be_eq<'tcx>( + tcx: TyCtxt<'tcx>, + canonical: Canonical<'tcx, (ParamEnv<'tcx>, Ty<'tcx>, Ty<'tcx>)>, +) -> Result<(), NoSolution> { + let (infcx, (param_env, ty_a, ty_b), _) = + tcx.infer_ctxt().build_with_canonical(DUMMY_SP, &canonical); + let ocx = ObligationCtxt::new(&infcx); + + let result = ocx.eq(&ObligationCause::dummy(), param_env, ty_a, ty_b); + // use `select_where_possible` instead of `select_all_or_error` so that + // we don't get errors from obligations being ambiguous. + let errors = ocx.select_where_possible(); + + if errors.len() > 0 || result.is_err() { Err(NoSolution) } else { Ok(()) } +} |