From 0de403fede6539a8c89ed6fcca97123503d0f455 Mon Sep 17 00:00:00 2001
From: Jelle Raaijmakers <jelle@gmta.nl>
Date: Thu, 24 Oct 2024 22:36:28 +0200
Subject: [PATCH] AK+LibJS: Add `[[nodiscard]]` to `operator*` in common types

The order of precedence with the `*` operator sometimes makes it a bit
harder to detect whether or not the result is actually used. Let's fail
compilation if anyone tries to discard the result.
---
 AK/Iterator.h                          | 4 ++--
 AK/NonnullOwnPtr.h                     | 2 +-
 AK/NonnullRefPtr.h                     | 2 +-
 AK/Optional.h                          | 4 ++--
 AK/OwnPtr.h                            | 2 +-
 AK/RefPtr.h                            | 2 +-
 Userland/Libraries/LibJS/Heap/GCPtr.h  | 4 ++--
 Userland/Libraries/LibJS/Heap/Handle.h | 2 +-
 8 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/AK/Iterator.h b/AK/Iterator.h
index 6c7a6fd2464..7b49c01a61d 100644
--- a/AK/Iterator.h
+++ b/AK/Iterator.h
@@ -76,12 +76,12 @@ public:
         return SimpleIterator { *m_container, m_index + 1 };
     }
 
-    ALWAYS_INLINE constexpr ValueType const& operator*() const
+    [[nodiscard]] ALWAYS_INLINE constexpr ValueType const& operator*() const
     requires(IsConst<ValueType>)
     {
         return (*m_container)[m_index];
     }
-    ALWAYS_INLINE constexpr ValueType& operator*() const
+    [[nodiscard]] ALWAYS_INLINE constexpr ValueType& operator*() const
     requires(!IsConst<ValueType>)
     {
         return (*m_container)[m_index];
diff --git a/AK/NonnullOwnPtr.h b/AK/NonnullOwnPtr.h
index 62af8d7dfbd..2fc212bad72 100644
--- a/AK/NonnullOwnPtr.h
+++ b/AK/NonnullOwnPtr.h
@@ -101,7 +101,7 @@ public:
 
     ALWAYS_INLINE RETURNS_NONNULL T* operator->() const { return ptr(); }
 
-    ALWAYS_INLINE T& operator*() const { return *ptr(); }
+    [[nodiscard]] ALWAYS_INLINE T& operator*() const { return *ptr(); }
 
     ALWAYS_INLINE RETURNS_NONNULL operator T*() const { return ptr(); }
 
diff --git a/AK/NonnullRefPtr.h b/AK/NonnullRefPtr.h
index f3c14adf4ee..62a049c134f 100644
--- a/AK/NonnullRefPtr.h
+++ b/AK/NonnullRefPtr.h
@@ -168,7 +168,7 @@ public:
         return as_nonnull_ptr();
     }
 
-    ALWAYS_INLINE T& operator*() const
+    [[nodiscard]] ALWAYS_INLINE T& operator*() const
     {
         return *as_nonnull_ptr();
     }
diff --git a/AK/Optional.h b/AK/Optional.h
index d8df8a39be1..62b2a8303e2 100644
--- a/AK/Optional.h
+++ b/AK/Optional.h
@@ -274,8 +274,8 @@ public:
         return TRY(callback());
     }
 
-    ALWAYS_INLINE T const& operator*() const { return value(); }
-    ALWAYS_INLINE T& operator*() { return value(); }
+    [[nodiscard]] ALWAYS_INLINE T const& operator*() const { return value(); }
+    [[nodiscard]] ALWAYS_INLINE T& operator*() { return value(); }
 
     ALWAYS_INLINE T const* operator->() const { return &value(); }
     ALWAYS_INLINE T* operator->() { return &value(); }
diff --git a/AK/OwnPtr.h b/AK/OwnPtr.h
index 7d2af97bb06..3d6e3650893 100644
--- a/AK/OwnPtr.h
+++ b/AK/OwnPtr.h
@@ -140,7 +140,7 @@ public:
         return m_ptr;
     }
 
-    T& operator*() const
+    [[nodiscard]] T& operator*() const
     {
         VERIFY(m_ptr);
         return *m_ptr;
diff --git a/AK/RefPtr.h b/AK/RefPtr.h
index 1aae365bf3c..4276b82b786 100644
--- a/AK/RefPtr.h
+++ b/AK/RefPtr.h
@@ -244,7 +244,7 @@ public:
         return as_nonnull_ptr();
     }
 
-    ALWAYS_INLINE T& operator*() const
+    [[nodiscard]] ALWAYS_INLINE T& operator*() const
     {
         return *as_nonnull_ptr();
     }
diff --git a/Userland/Libraries/LibJS/Heap/GCPtr.h b/Userland/Libraries/LibJS/Heap/GCPtr.h
index b5d25d57c0b..2ddef6058da 100644
--- a/Userland/Libraries/LibJS/Heap/GCPtr.h
+++ b/Userland/Libraries/LibJS/Heap/GCPtr.h
@@ -62,7 +62,7 @@ public:
 
     RETURNS_NONNULL T* operator->() const { return m_ptr; }
 
-    T& operator*() const { return *m_ptr; }
+    [[nodiscard]] T& operator*() const { return *m_ptr; }
 
     RETURNS_NONNULL T* ptr() const { return m_ptr; }
 
@@ -169,7 +169,7 @@ public:
         return m_ptr;
     }
 
-    T& operator*() const
+    [[nodiscard]] T& operator*() const
     {
         ASSERT(m_ptr);
         return *m_ptr;
diff --git a/Userland/Libraries/LibJS/Heap/Handle.h b/Userland/Libraries/LibJS/Heap/Handle.h
index 55a2d082520..b9d579cf8d6 100644
--- a/Userland/Libraries/LibJS/Heap/Handle.h
+++ b/Userland/Libraries/LibJS/Heap/Handle.h
@@ -96,7 +96,7 @@ public:
         return cell();
     }
 
-    T& operator*() const
+    [[nodiscard]] T& operator*() const
     {
         return *cell();
     }