1 files changed, 79 insertions, 0 deletions
diff --git a/compiler/rustc_infer/src/traits/structural_impls.rs b/compiler/rustc_infer/src/traits/structural_impls.rs
new file mode 100644
index 000000000..573d2d1e3
--- /dev/null
+++ b/compiler/rustc_infer/src/traits/structural_impls.rs
@@ -0,0 +1,79 @@
+use crate::traits;
+use crate::traits::project::Normalized;
+use rustc_middle::ty;
+use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable};
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitor};
+
+use std::fmt;
+use std::ops::ControlFlow;
+
+// Structural impls for the structs in `traits`.
+
+impl<'tcx, T: fmt::Debug> fmt::Debug for Normalized<'tcx, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Normalized({:?}, {:?})", self.value, self.obligations)
+    }
+}
+
+impl<'tcx, O: fmt::Debug> fmt::Debug for traits::Obligation<'tcx, O> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if ty::tls::with(|tcx| tcx.sess.verbose()) {
+            write!(
+                f,
+                "Obligation(predicate={:?}, cause={:?}, param_env={:?}, depth={})",
+                self.predicate, self.cause, self.param_env, self.recursion_depth
+            )
+        } else {
+            write!(f, "Obligation(predicate={:?}, depth={})", self.predicate, self.recursion_depth)
+        }
+    }
+}
+
+impl<'tcx> fmt::Debug for traits::FulfillmentError<'tcx> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "FulfillmentError({:?},{:?})", self.obligation, self.code)
+    }
+}
+
+impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            super::CodeSelectionError(ref e) => write!(f, "{:?}", e),
+            super::CodeProjectionError(ref e) => write!(f, "{:?}", e),
+            super::CodeSubtypeError(ref a, ref b) => {
+                write!(f, "CodeSubtypeError({:?}, {:?})", a, b)
+            }
+            super::CodeConstEquateError(ref a, ref b) => {
+                write!(f, "CodeConstEquateError({:?}, {:?})", a, b)
+            }
+            super::CodeAmbiguity => write!(f, "Ambiguity"),
+        }
+    }
+}
+
+impl<'tcx> fmt::Debug for traits::MismatchedProjectionTypes<'tcx> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "MismatchedProjectionTypes({:?})", self.err)
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////
+// TypeFoldable implementations.
+
+impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Obligation<'tcx, O> {
+    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+        Ok(traits::Obligation {
+            cause: self.cause,
+            recursion_depth: self.recursion_depth,
+            predicate: self.predicate.try_fold_with(folder)?,
+            param_env: self.param_env.try_fold_with(folder)?,
+        })
+    }
+}
+
+impl<'tcx, O: TypeVisitable<'tcx>> TypeVisitable<'tcx> for traits::Obligation<'tcx, O> {
+    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+        self.predicate.visit_with(visitor)?;
+        self.param_env.visit_with(visitor)
+    }
+}