From 55383998b1d6440ea2653b9efd4286ab4eb11805 Mon Sep 17 00:00:00 2001
From: Jonne Ransijn <jonne@yyny.dev>
Date: Mon, 25 Nov 2024 12:54:43 +0100
Subject: [PATCH] AK: Use `Noncopyable.h` in `Optional<T&>`

This makes them trivially copyable/movable, silencing

> "parameter is copied for each invocation"

warnings on `Optional<T&>`, which are unnecessairy,
since `Optional<T&>` is just a trivially copyable pointer.

This creates a slight change in behaviour when moving out of an
`Optional<T&>`, since the moved-from optional no longer gets cleared.

Moved-from values should be considered to be in an undefined state,
and if clearing a moved-from `Optional<T&>` is desired, you should be
using `Optional<T&>::release_value()` instead.
---
 AK/Optional.h             | 33 +++------------------------------
 Tests/AK/TestOptional.cpp |  1 -
 2 files changed, 3 insertions(+), 31 deletions(-)

diff --git a/AK/Optional.h b/AK/Optional.h
index 7519072a8ad..4453f51d875 100644
--- a/AK/Optional.h
+++ b/AK/Optional.h
@@ -336,6 +336,9 @@ private:
 
 template<typename T>
 requires(IsLvalueReference<T>) class [[nodiscard]] Optional<T> {
+    AK_MAKE_DEFAULT_COPYABLE(Optional);
+    AK_MAKE_DEFAULT_MOVABLE(Optional);
+
     template<typename>
     friend class Optional;
 
@@ -369,17 +372,6 @@ public:
     {
     }
 
-    ALWAYS_INLINE Optional(Optional const& other)
-        : m_pointer(other.m_pointer)
-    {
-    }
-
-    ALWAYS_INLINE Optional(Optional&& other)
-        : m_pointer(other.m_pointer)
-    {
-        other.m_pointer = nullptr;
-    }
-
     template<typename U>
     ALWAYS_INLINE Optional(Optional<U>& other)
     requires(CanBePlacedInOptional<U>)
@@ -402,25 +394,6 @@ public:
         other.m_pointer = nullptr;
     }
 
-    ALWAYS_INLINE Optional& operator=(Optional& other)
-    {
-        m_pointer = other.m_pointer;
-        return *this;
-    }
-
-    ALWAYS_INLINE Optional& operator=(Optional const& other)
-    {
-        m_pointer = other.m_pointer;
-        return *this;
-    }
-
-    ALWAYS_INLINE Optional& operator=(Optional&& other)
-    {
-        m_pointer = other.m_pointer;
-        other.m_pointer = nullptr;
-        return *this;
-    }
-
     template<typename U>
     ALWAYS_INLINE Optional& operator=(Optional<U>& other)
     requires(CanBePlacedInOptional<U>)
diff --git a/Tests/AK/TestOptional.cpp b/Tests/AK/TestOptional.cpp
index 2c0f3f49a57..a30e9ec3893 100644
--- a/Tests/AK/TestOptional.cpp
+++ b/Tests/AK/TestOptional.cpp
@@ -247,7 +247,6 @@ TEST_CASE(move_optional_reference)
     y = move(x);
     EXPECT_EQ(y.has_value(), true);
     EXPECT_EQ(y.value(), 3);
-    EXPECT_EQ(x.has_value(), false);
 }
 
 TEST_CASE(short_notation_reference)