From 3db2efbb5eb57b15b991dc4c6fd1ce3ca3ee6dc9 Mon Sep 17 00:00:00 2001
From: Lokathor <zefria@gmail.com>
Date: Thu, 4 Mar 2021 19:31:11 -0700
Subject: [PATCH 1/5] add the bool::not method.

---
 compiler/rustc_feature/src/active.rs | 3 +++
 library/core/src/bool.rs             | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index 8ee995a59d80..a7c3c7e6bfa4 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -644,6 +644,9 @@ declare_features! (
     /// Allows associated types in inherent impls.
     (active, inherent_associated_types, "1.52.0", Some(8995), None),
 
+    /// Adds the `bool::not` method so that you don't need `core::ops::Not` imported.
+    (active, bool_not_method, "1.52.0", None, None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------
diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs
index 00164c631b30..0a06eed3423a 100644
--- a/library/core/src/bool.rs
+++ b/library/core/src/bool.rs
@@ -31,4 +31,9 @@ impl bool {
     pub fn then<T, F: FnOnce() -> T>(self, f: F) -> Option<T> {
         if self { Some(f()) } else { None }
     }
+
+    #[unstable(feature = "bool_not_method", issue = "none")]
+    pub fn not(self) -> Self {
+        !self
+    }
 }

From a25f6f7105d404b49ca4a79b2ca515e0af48d0ec Mon Sep 17 00:00:00 2001
From: Lokathor <zefria@gmail.com>
Date: Thu, 4 Mar 2021 19:38:33 -0700
Subject: [PATCH 2/5] document the method.

---
 library/core/src/bool.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs
index 0a06eed3423a..b9ee1f02c72b 100644
--- a/library/core/src/bool.rs
+++ b/library/core/src/bool.rs
@@ -32,6 +32,14 @@ impl bool {
         if self { Some(f()) } else { None }
     }
 
+    /// Returns the opposite value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// assert_eq!(false.not(), true);
+    /// assert_eq!(true.not(), false);
+    /// ```
     #[unstable(feature = "bool_not_method", issue = "none")]
     pub fn not(self) -> Self {
         !self

From 828aa80806e6b3e106659754289d6bd92d76149a Mon Sep 17 00:00:00 2001
From: Lokathor <zefria@gmail.com>
Date: Thu, 4 Mar 2021 21:15:38 -0700
Subject: [PATCH 3/5] take out the new feature, we don't need a compiler
 feature.

---
 compiler/rustc_feature/src/active.rs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index a7c3c7e6bfa4..8ee995a59d80 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -644,9 +644,6 @@ declare_features! (
     /// Allows associated types in inherent impls.
     (active, inherent_associated_types, "1.52.0", Some(8995), None),
 
-    /// Adds the `bool::not` method so that you don't need `core::ops::Not` imported.
-    (active, bool_not_method, "1.52.0", None, None),
-
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------

From 663ce13ff6a7ad01bfdbebdbcf4d46418031b91a Mon Sep 17 00:00:00 2001
From: Lokathor <zefria@gmail.com>
Date: Wed, 10 Mar 2021 19:41:18 -0700
Subject: [PATCH 4/5] add const modifier and inline attribute to bool::not

---
 library/core/src/bool.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs
index b9ee1f02c72b..38b4d871250a 100644
--- a/library/core/src/bool.rs
+++ b/library/core/src/bool.rs
@@ -41,7 +41,8 @@ impl bool {
     /// assert_eq!(true.not(), false);
     /// ```
     #[unstable(feature = "bool_not_method", issue = "none")]
-    pub fn not(self) -> Self {
+    #[inline]
+    pub const fn not(self) -> Self {
         !self
     }
 }

From 00c542688e0111c83eeaa30557731a15071c0616 Mon Sep 17 00:00:00 2001
From: Lokathor <zefria@gmail.com>
Date: Sun, 28 Mar 2021 11:06:01 -0600
Subject: [PATCH 5/5] improve documentation.

---
 library/core/src/bool.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/library/core/src/bool.rs b/library/core/src/bool.rs
index 38b4d871250a..01f53b3138a2 100644
--- a/library/core/src/bool.rs
+++ b/library/core/src/bool.rs
@@ -34,11 +34,16 @@ impl bool {
 
     /// Returns the opposite value.
     ///
+    /// This is identical in functionality to usage of the `!` operator, it's
+    /// simply an alternate way to write it. Because it's post-fix instead of
+    /// pre-fix, it is often more readable within chained function call
+    /// expressions.
+    ///
     /// # Examples
     ///
     /// ```
-    /// assert_eq!(false.not(), true);
-    /// assert_eq!(true.not(), false);
+    /// assert_eq!(!true, true.not());
+    /// assert_eq!(!false, false.not());
     /// ```
     #[unstable(feature = "bool_not_method", issue = "none")]
     #[inline]