manually impl more traits for WithOptParam

Author: lcnr

src/librustc_middle/ty/mod.rs

@@ -1576,7 +1576,7 @@ pub type PlaceholderConst = Placeholder<BoundVar>;
 /// Luckily we only need to deal with const arguments once we
 /// know their corresponding parameters. We (ab)use this by
 /// calling `type_of(param_did)` for these arguments.
-#[derive(Copy, Clone, Debug, Hash, HashStable, TypeFoldable, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)]
 pub struct WithOptParam<T> {
     pub did: T,
     /// The `DefId` of the corresponding generic paramter in case `did` is
@@ -1586,13 +1586,27 @@ pub struct WithOptParam<T> {
     pub param_did: Option<DefId>,
 }
 
-// We manually implement comparisions as the `param_did` can be ignored.
+// We manually implement most traits for `WithOptParam`
+// as the `param_did` is redundant.
+
 impl<T: PartialEq> PartialEq for WithOptParam<T> {
     fn eq(&self, other: &Self) -> bool {
         self.did == other.did
     }
 }
 
+impl<T: Hash> Hash for WithOptParam<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.did.hash(state);
+    }
+}
+
+impl<CTX, T: HashStable<CTX>> HashStable<CTX> for WithOptParam<T> {
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        self.did.hash_stable(hcx, hasher);
+    }
+}
+
 impl<T: Eq> Eq for WithOptParam<T> {}
 
 impl<T: PartialOrd> PartialOrd for WithOptParam<T> {

src/librustc_middle/ty/structural_impls.rs

@@ -261,23 +261,23 @@ CloneTypeFoldableAndLiftImpls! {
     (),
     bool,
     usize,
-    ::rustc_target::abi::VariantIdx,
+    rustc_target::abi::VariantIdx,
     u64,
     String,
     crate::middle::region::Scope,
-    ::rustc_ast::ast::FloatTy,
-    ::rustc_ast::ast::InlineAsmOptions,
-    ::rustc_ast::ast::InlineAsmTemplatePiece,
-    ::rustc_ast::ast::NodeId,
-    ::rustc_span::symbol::Symbol,
-    ::rustc_hir::def::Res,
-    ::rustc_hir::def_id::DefId,
-    ::rustc_hir::LlvmInlineAsmInner,
-    ::rustc_hir::MatchSource,
-    ::rustc_hir::Mutability,
-    ::rustc_hir::Unsafety,
-    ::rustc_target::asm::InlineAsmRegOrRegClass,
-    ::rustc_target::spec::abi::Abi,
+    rustc_ast::ast::FloatTy,
+    rustc_ast::ast::InlineAsmOptions,
+    rustc_ast::ast::InlineAsmTemplatePiece,
+    rustc_ast::ast::NodeId,
+    rustc_span::symbol::Symbol,
+    rustc_hir::def::Res,
+    rustc_hir::def_id::DefId,
+    rustc_hir::LlvmInlineAsmInner,
+    rustc_hir::MatchSource,
+    rustc_hir::Mutability,
+    rustc_hir::Unsafety,
+    rustc_target::asm::InlineAsmRegOrRegClass,
+    rustc_target::spec::abi::Abi,
     crate::mir::Local,
     crate::mir::Promoted,
     crate::traits::Reveal,
@@ -299,6 +299,8 @@ CloneTypeFoldableAndLiftImpls! {
     crate::ty::RegionVid,
     crate::ty::UniverseIndex,
     crate::ty::Variance,
+    crate::ty::WithOptParam<rustc_hir::def_id::LocalDefId>,
+    crate::ty::WithOptParam<rustc_hir::def_id::DefId>,
     ::rustc_span::Span,
 }