Rollup merge of #61261 - spastorino:is-union-return-ty, r=oli-obk

[rust.git] / src / librustc / ty / error.rs

diff --git a/src/librustc/ty/error.rs b/src/librustc/ty/error.rs
index 74d0a29bcff00df8b600b5fcf0338032748be070..09426fe19e11eac2c21991aae10fc21dd6c9dc01 100644 (file)
--- a/src/librustc/ty/error.rs
+++ b/src/librustc/ty/error.rs
@@ -44,6 +44,8 @@ pub enum TypeError<'tcx> {
     ProjectionMismatched(ExpectedFound<DefId>),
     ProjectionBoundsLength(ExpectedFound<usize>),
     ExistentialMismatch(ExpectedFound<&'tcx ty::List<ty::ExistentialPredicate<'tcx>>>),
+
+    ConstMismatch(ExpectedFound<&'tcx ty::Const<'tcx>>),
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug, Copy)]
@@ -78,6 +80,12 @@ fn report_maybe_different(f: &mut fmt::Formatter<'_>,
             }
         };
 
+        macro_rules! pluralise {
+            ($x:expr) => {
+                if $x != 1 { "s" } else { "" }
+            };
+        }
+
         match *self {
             CyclicTy(_) => write!(f, "cyclic type of infinite size"),
             Mismatch => write!(f, "types differ"),
@@ -92,17 +100,21 @@ fn report_maybe_different(f: &mut fmt::Formatter<'_>,
                        values.found)
             }
             Mutability => write!(f, "types differ in mutability"),
-            FixedArraySize(values) => {
-                write!(f, "expected an array with a fixed size of {} elements, \
-                           found one with {} elements",
+            TupleSize(values) => {
+                write!(f, "expected a tuple with {} element{}, \
+                           found one with {} element{}",
                        values.expected,
-                       values.found)
+                       pluralise!(values.expected),
+                       values.found,
+                       pluralise!(values.found))
             }
-            TupleSize(values) => {
-                write!(f, "expected a tuple with {} elements, \
-                           found one with {} elements",
+            FixedArraySize(values) => {
+                write!(f, "expected an array with a fixed size of {} element{}, \
+                           found one with {} element{}",
                        values.expected,
-                       values.found)
+                       pluralise!(values.expected),
+                       values.found,
+                       pluralise!(values.found))
             }
             ArgCount => {
                 write!(f, "incorrect number of function parameters")
@@ -155,14 +167,18 @@ fn report_maybe_different(f: &mut fmt::Formatter<'_>,
                        tcx.def_path_str(values.found))
             }),
             ProjectionBoundsLength(ref values) => {
-                write!(f, "expected {} associated type bindings, found {}",
+                write!(f, "expected {} associated type binding{}, found {}",
                        values.expected,
+                       pluralise!(values.expected),
                        values.found)
             },
             ExistentialMismatch(ref values) => {
                 report_maybe_different(f, &format!("trait `{}`", values.expected),
                                        &format!("trait `{}`", values.found))
             }
+            ConstMismatch(ref values) => {
+                write!(f, "expected `{}`, found `{}`", values.expected, values.found)
+            }
         }
     }
 }