Auto merge of #25523 - nham:remove_E0068, r=alexcrichton

A built-in feature enabling the dereferencing of newtype structs was removed
in PR https://github.com/rust-lang/rust/pull/11188, and this error (E0068) was added at the same time to warn of
its removal. It seems to make sense to remove the error now, given that
the obsolete feature it is warning about was removed nearly a year and a
half ago.

1 files changed, 4 insertions, 20 deletions

diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index f13305bba34..db39d3c05ed 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -3153,26 +3153,10 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
                                                            Some(&**oprnd), oprnd_t, lvalue_pref) {
                             Some(mt) => mt.ty,
                             None => {
-                                let is_newtype = match oprnd_t.sty {
-                                    ty::ty_struct(did, substs) => {
-                                        let fields = ty::struct_fields(fcx.tcx(), did, substs);
-                                        fields.len() == 1
-                                        && fields[0].name ==
-                                        token::special_idents::unnamed_field.name
-                                    }
-                                    _ => false
-                                };
-                                if is_newtype {
-                                    // This is an obsolete struct deref
-                                    span_err!(tcx.sess, expr.span, E0068,
-                                        "single-field tuple-structs can \
-                                         no longer be dereferenced");
-                                } else {
-                                    fcx.type_error_message(expr.span, |actual| {
-                                        format!("type `{}` cannot be \
-                                                dereferenced", actual)
-                                    }, oprnd_t, None);
-                                }
+                                fcx.type_error_message(expr.span, |actual| {
+                                    format!("type `{}` cannot be \
+                                            dereferenced", actual)
+                                }, oprnd_t, None);
                                 tcx.types.err
                             }
                         }