2 files changed, 13 insertions, 10 deletions
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 63e5bc50513..af0c3026c66 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -2300,3 +2300,16 @@ impl HelpUseLatestEdition {
         }
     }
 }
+
+#[derive(Diagnostic)]
+#[diag(parse_box_syntax_removed)]
+pub struct BoxSyntaxRemoved<'a> {
+    #[primary_span]
+    #[suggestion(
+        code = "Box::new({code})",
+        applicability = "machine-applicable",
+        style = "verbose"
+    )]
+    pub span: Span,
+    pub code: &'a str,
+}
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index e00eda47c66..27516716286 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -607,9 +607,6 @@ impl<'a> Parser<'a> {
                 let operand_expr = this.parse_expr_dot_or_call(Default::default())?;
                 this.recover_from_prefix_increment(operand_expr, pre_span, starts_stmt)
             }
-            token::Ident(..) if this.token.is_keyword(kw::Box) => {
-                make_it!(this, attrs, |this, _| this.parse_expr_box(lo))
-            }
             token::Ident(..) if this.may_recover() && this.is_mistaken_not_ident_negation() => {
                 make_it!(this, attrs, |this, _| this.recover_not_expr(lo))
             }
@@ -636,13 +633,6 @@ impl<'a> Parser<'a> {
         self.parse_expr_unary(lo, UnOp::Not)
     }
 
-    /// Parse `box expr`.
-    fn parse_expr_box(&mut self, lo: Span) -> PResult<'a, (Span, ExprKind)> {
-        let (span, expr) = self.parse_expr_prefix_common(lo)?;
-        self.sess.gated_spans.gate(sym::box_syntax, span);
-        Ok((span, ExprKind::Box(expr)))
-    }
-
     fn is_mistaken_not_ident_negation(&self) -> bool {
         let token_cannot_continue_expr = |t: &Token| match t.uninterpolate().kind {
             // These tokens can start an expression after `!`, but