enable `rust_2018_idioms` for doctests

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

4 files changed, 5 insertions, 5 deletions

diff --git a/library/alloc/src/vec/drain.rs b/library/alloc/src/vec/drain.rs
index 3091efabd68..f0b63759ac7 100644
--- a/library/alloc/src/vec/drain.rs
+++ b/library/alloc/src/vec/drain.rs
@@ -16,7 +16,7 @@ use super::Vec;
 ///
 /// ```
 /// let mut v = vec![0, 1, 2];
-/// let iter: std::vec::Drain<_> = v.drain(..);
+/// let iter: std::vec::Drain<'_, _> = v.drain(..);
 /// ```
 #[stable(feature = "drain", since = "1.6.0")]
 pub struct Drain<
diff --git a/library/alloc/src/vec/drain_filter.rs b/library/alloc/src/vec/drain_filter.rs
index 650f9213890..21b09023462 100644
--- a/library/alloc/src/vec/drain_filter.rs
+++ b/library/alloc/src/vec/drain_filter.rs
@@ -16,7 +16,7 @@ use super::Vec;
 /// #![feature(drain_filter)]
 ///
 /// let mut v = vec![0, 1, 2];
-/// let iter: std::vec::DrainFilter<_, _> = v.drain_filter(|x| *x % 2 == 0);
+/// let iter: std::vec::DrainFilter<'_, _, _> = v.drain_filter(|x| *x % 2 == 0);
 /// ```
 #[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")]
 #[derive(Debug)]
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 765c095e37b..97da6f06b70 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -3142,8 +3142,8 @@ where
     ///
     /// ```
     /// # use std::borrow::Cow;
-    /// let o: Cow<[i32]> = Cow::Owned(vec![1, 2, 3]);
-    /// let b: Cow<[i32]> = Cow::Borrowed(&[1, 2, 3]);
+    /// let o: Cow<'_, [i32]> = Cow::Owned(vec![1, 2, 3]);
+    /// let b: Cow<'_, [i32]> = Cow::Borrowed(&[1, 2, 3]);
     /// assert_eq!(Vec::from(o), Vec::from(b));
     /// ```
     fn from(s: Cow<'a, [T]>) -> Vec<T> {
diff --git a/library/alloc/src/vec/splice.rs b/library/alloc/src/vec/splice.rs
index 1861147fe72..852fdcc3f5c 100644
--- a/library/alloc/src/vec/splice.rs
+++ b/library/alloc/src/vec/splice.rs
@@ -14,7 +14,7 @@ use super::{Drain, Vec};
 /// ```
 /// let mut v = vec![0, 1, 2];
 /// let new = [7, 8];
-/// let iter: std::vec::Splice<_> = v.splice(1.., new);
+/// let iter: std::vec::Splice<'_, _> = v.splice(1.., new);
 /// ```
 #[derive(Debug)]
 #[stable(feature = "vec_splice", since = "1.21.0")]