enable `rust_2018_idioms` for doctests

Signed-off-by: ozkanonur <work@onurozkan.dev>

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index d07355a4154..8a511d8b5fb 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1474,6 +1474,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     /// Given a function definition like:
     ///
     /// ```rust
+    /// use std::fmt::Debug;
+    ///
     /// fn test<'a, T: Debug>(x: &'a T) -> impl Debug + 'a {
     ///     x
     /// }
@@ -1481,13 +1483,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     ///
     /// we will create a TAIT definition in the HIR like
     ///
-    /// ```
+    /// ```rust,ignore (pseudo-Rust)
     /// type TestReturn<'a, T, 'x> = impl Debug + 'x
     /// ```
     ///
     /// and return a type like `TestReturn<'static, T, 'a>`, so that the function looks like:
     ///
-    /// ```rust
+    /// ```rust,ignore (pseudo-Rust)
     /// fn test<'a, T: Debug>(x: &'a T) -> TestReturn<'static, T, 'a>
     /// ```
     ///