diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/mod.rs | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 63870d97146..4189a81632a 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -31,6 +31,7 @@ use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_errors::ErrorReported; use rustc_hir as hir; use rustc_hir::def_id::DefId; +use rustc_hir::Constness; use rustc_middle::dep_graph::{DepKind, DepNodeIndex}; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::ty::fast_reject; @@ -1335,7 +1336,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { (BuiltinCandidate { has_nested: false } | DiscriminantKindCandidate, _) => true, (_, BuiltinCandidate { has_nested: false } | DiscriminantKindCandidate) => false, - (ParamCandidate(..), ParamCandidate(..)) => false, + (ParamCandidate(other), ParamCandidate(victim)) => { + if other.value == victim.value && victim.constness == Constness::NotConst { + // Drop otherwise equivalent non-const candidates in favor of const candidates. + true + } else { + false + } + } // Global bounds from the where clause should be ignored // here (see issue #50825). Otherwise, we have a where |