diff options
| -rw-r--r-- | src/librustc/hir/lowering/expr.rs | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/src/librustc/hir/lowering/expr.rs b/src/librustc/hir/lowering/expr.rs index d5fcc0ef6ed..73db762a64b 100644 --- a/src/librustc/hir/lowering/expr.rs +++ b/src/librustc/hir/lowering/expr.rs @@ -235,11 +235,20 @@ impl LoweringContext<'_> { /// ``` fn lower_expr_let(&mut self, span: Span, pat: &Pat, scrutinee: &Expr) -> hir::ExprKind { // If we got here, the `let` expression is not allowed. - self.sess - .struct_span_err(span, "`let` expressions are not supported here") - .note("only supported directly in conditions of `if`- and `while`-expressions") - .note("as well as when nested within `&&` and parenthesis in those conditions") - .emit(); + + if self.sess.opts.unstable_features.is_nightly_build() { + self.sess + .struct_span_err(span, "`let` expressions are not supported here") + .note("only supported directly in conditions of `if`- and `while`-expressions") + .note("as well as when nested within `&&` and parenthesis in those conditions") + .emit(); + } + else { + self.sess + .struct_span_err(span, "expected expression, found statement (`let`)") + .note("variable declaration using `let` is a statement") + .emit(); + } // For better recovery, we emit: // ``` |