Remove trailing space in error message

compiler/rustc_middle/src/ty/error.rs

@@ -232,7 +232,7 @@ impl<'tcx> ty::TyS<'tcx> {
                 let n = tcx.lift(&n).unwrap();
                 match n.try_eval_usize(tcx, ty::ParamEnv::empty()) {
                     _ if t.is_simple_ty() => format!("array `{}`", self).into(),
-                    Some(n) => format!("array of {} element{} ", n, pluralize!(n)).into(),
+                    Some(n) => format!("array of {} element{}", n, pluralize!(n)).into(),
                     None => "array".into(),
                 }
             }

src/test/ui/slice-to-vec-comparison.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let a = &[];
+    let b: &Vec<u8> = &vec![];
+    a > b;
+    //~^ ERROR mismatched types
+}

src/test/ui/slice-to-vec-comparison.stderr

@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/slice-to-vec-comparison.rs:4:9
+   |
+LL |     a > b;
+   |         ^ expected array of 0 elements, found struct `Vec`
+   |
+   = note: expected reference `&[_; 0]`
+              found reference `&Vec<u8>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.