Rollup merge of #41249 - GuillaumeGomez:rustdoc-render, r=steveklabnik,frewsxcv

[rust.git] / src / librustc / traits / object_safety.rs

diff --git a/src/librustc/traits/object_safety.rs b/src/librustc/traits/object_safety.rs
index 60808fbc741fb9898bde442a1f568641256b68d9..d190635bec3063ce3c0e8193fba6cde6942e0800 100644 (file)
--- a/src/librustc/traits/object_safety.rs
+++ b/src/librustc/traits/object_safety.rs
@@ -23,6 +23,7 @@
 use traits;
 use ty::{self, Ty, TyCtxt, TypeFoldable};
 use ty::subst::Substs;
+use std::borrow::Cow;
 use syntax::ast;
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
@@ -38,6 +39,25 @@ pub enum ObjectSafetyViolation {
     Method(ast::Name, MethodViolationCode),
 }
 
+impl ObjectSafetyViolation {
+    pub fn error_msg(&self) -> Cow<'static, str> {
+        match *self {
+            ObjectSafetyViolation::SizedSelf =>
+                "the trait cannot require that `Self : Sized`".into(),
+            ObjectSafetyViolation::SupertraitSelf =>
+                "the trait cannot use `Self` as a type parameter \
+                 in the supertraits or where-clauses".into(),
+            ObjectSafetyViolation::Method(name, MethodViolationCode::StaticMethod) =>
+                format!("method `{}` has no receiver", name).into(),
+            ObjectSafetyViolation::Method(name, MethodViolationCode::ReferencesSelf) =>
+                format!("method `{}` references the `Self` type \
+                         in its arguments or return type", name).into(),
+            ObjectSafetyViolation::Method(name, MethodViolationCode::Generic) =>
+                format!("method `{}` has generic type parameters", name).into(),
+        }
+    }
+}
+
 /// Reasons a method might not be object-safe.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
 pub enum MethodViolationCode {
@@ -158,6 +178,7 @@ fn predicates_reference_self(
                     ty::Predicate::TypeOutlives(..) |
                     ty::Predicate::RegionOutlives(..) |
                     ty::Predicate::ClosureKind(..) |
+                    ty::Predicate::Subtype(..) |
                     ty::Predicate::Equate(..) => {
                         false
                     }
@@ -189,6 +210,7 @@ fn generics_require_sized_self(self, def_id: DefId) -> bool {
                     ty::Predicate::Projection(..) |
                     ty::Predicate::Trait(..) |
                     ty::Predicate::Equate(..) |
+                    ty::Predicate::Subtype(..) |
                     ty::Predicate::RegionOutlives(..) |
                     ty::Predicate::WellFormed(..) |
                     ty::Predicate::ObjectSafe(..) |