Make OpaqueEncoder private.

Author: cjgillot

compiler/rustc_middle/src/ty/codec.rs

@@ -50,22 +50,6 @@ impl<'tcx, E: TyEncoder<'tcx>> EncodableWithShorthand<'tcx, E> for ty::Predicate
     }
 }
 
-pub trait OpaqueEncoder: Encoder {
-    fn opaque(&mut self) -> &mut rustc_serialize::opaque::Encoder;
-    fn encoder_position(&self) -> usize;
-}
-
-impl OpaqueEncoder for rustc_serialize::opaque::Encoder {
-    #[inline]
-    fn opaque(&mut self) -> &mut rustc_serialize::opaque::Encoder {
-        self
-    }
-    #[inline]
-    fn encoder_position(&self) -> usize {
-        self.position()
-    }
-}
-
 pub trait TyEncoder<'tcx>: Encoder {
     const CLEAR_CROSS_CRATE: bool;
 

compiler/rustc_middle/src/ty/query/on_disk_cache.rs

@@ -1,7 +1,7 @@
 use crate::dep_graph::{DepNodeIndex, SerializedDepNodeIndex};
 use crate::mir::interpret::{AllocDecodingSession, AllocDecodingState};
 use crate::mir::{self, interpret};
-use crate::ty::codec::{OpaqueEncoder, RefDecodable, TyDecoder, TyEncoder};
+use crate::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
 use crate::ty::context::TyCtxt;
 use crate::ty::{self, Ty};
 use rustc_data_structures::fingerprint::{Fingerprint, FingerprintDecoder, FingerprintEncoder};
@@ -764,6 +764,23 @@ impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [Span] {
 
 //- ENCODING -------------------------------------------------------------------
 
+/// This trait is a hack to work around specialization bug #55243.
+trait OpaqueEncoder: Encoder {
+    fn opaque(&mut self) -> &mut opaque::Encoder;
+    fn encoder_position(&self) -> usize;
+}
+
+impl OpaqueEncoder for opaque::Encoder {
+    #[inline]
+    fn opaque(&mut self) -> &mut opaque::Encoder {
+        self
+    }
+    #[inline]
+    fn encoder_position(&self) -> usize {
+        self.position()
+    }
+}
+
 /// An encoder that can write the incr. comp. cache.
 struct CacheEncoder<'a, 'tcx, E: OpaqueEncoder> {
     tcx: TyCtxt<'tcx>,