From f65b039c442bb28451bb4bcfc6a91bff76bd0e66 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 21 Jul 2021 18:18:29 +0200
Subject: [PATCH] AK: Sprinkle [[nodiscard]] on HashMap and HashTable

---
 AK/HashMap.h   | 20 ++++++++++----------
 AK/HashTable.h | 26 +++++++++++++-------------
 2 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/AK/HashMap.h b/AK/HashMap.h
index c1823b9f4e..e5e9bb66fd 100644
--- a/AK/HashMap.h
+++ b/AK/HashMap.h
@@ -71,26 +71,26 @@ public:
     using IteratorType = typename HashTableType::Iterator;
     using ConstIteratorType = typename HashTableType::ConstIterator;
 
-    IteratorType begin() { return m_table.begin(); }
-    IteratorType end() { return m_table.end(); }
-    IteratorType find(const K& key)
+    [[nodiscard]] IteratorType begin() { return m_table.begin(); }
+    [[nodiscard]] IteratorType end() { return m_table.end(); }
+    [[nodiscard]] IteratorType find(const K& key)
     {
         return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(key, entry.key); });
     }
     template<typename TUnaryPredicate>
-    IteratorType find(unsigned hash, TUnaryPredicate predicate)
+    [[nodiscard]] IteratorType find(unsigned hash, TUnaryPredicate predicate)
     {
         return m_table.find(hash, predicate);
     }
 
-    ConstIteratorType begin() const { return m_table.begin(); }
-    ConstIteratorType end() const { return m_table.end(); }
-    ConstIteratorType find(const K& key) const
+    [[nodiscard]] ConstIteratorType begin() const { return m_table.begin(); }
+    [[nodiscard]] ConstIteratorType end() const { return m_table.end(); }
+    [[nodiscard]] ConstIteratorType find(const K& key) const
     {
         return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(key, entry.key); });
     }
     template<typename TUnaryPredicate>
-    ConstIteratorType find(unsigned hash, TUnaryPredicate predicate) const
+    [[nodiscard]] ConstIteratorType find(unsigned hash, TUnaryPredicate predicate) const
     {
         return m_table.find(hash, predicate);
     }
@@ -121,7 +121,7 @@ public:
         return (*it).value;
     }
 
-    bool contains(const K& key) const
+    [[nodiscard]] bool contains(const K& key) const
     {
         return find(key) != end();
     }
@@ -139,7 +139,7 @@ public:
         return find(key)->value;
     }
 
-    Vector<K> keys() const
+    [[nodiscard]] Vector<K> keys() const
     {
         Vector<K> list;
         list.ensure_capacity(size());
diff --git a/AK/HashTable.h b/AK/HashTable.h
index 8ad3566f84..de34a85882 100644
--- a/AK/HashTable.h
+++ b/AK/HashTable.h
@@ -197,7 +197,7 @@ public:
         rehash(capacity * 2);
     }
 
-    bool contains(const T& value) const
+    [[nodiscard]] bool contains(T const& value) const
     {
         return find(value) != end();
     }
@@ -206,7 +206,7 @@ public:
         OrderedHashTableIterator<HashTable, T, BucketType>,
         HashTableIterator<HashTable, T, BucketType>>;
 
-    Iterator begin()
+    [[nodiscard]] Iterator begin()
     {
         if constexpr (IsOrdered)
             return Iterator(m_collection_data.head);
@@ -218,7 +218,7 @@ public:
         return end();
     }
 
-    Iterator end()
+    [[nodiscard]] Iterator end()
     {
         return Iterator(nullptr);
     }
@@ -227,7 +227,7 @@ public:
         OrderedHashTableIterator<const HashTable, const T, const BucketType>,
         HashTableIterator<const HashTable, const T, const BucketType>>;
 
-    ConstIterator begin() const
+    [[nodiscard]] ConstIterator begin() const
     {
         if constexpr (IsOrdered)
             return ConstIterator(m_collection_data.head);
@@ -239,7 +239,7 @@ public:
         return end();
     }
 
-    ConstIterator end() const
+    [[nodiscard]] ConstIterator end() const
     {
         return ConstIterator(nullptr);
     }
@@ -282,23 +282,23 @@ public:
     }
 
     template<typename TUnaryPredicate>
-    Iterator find(unsigned hash, TUnaryPredicate predicate)
+    [[nodiscard]] Iterator find(unsigned hash, TUnaryPredicate predicate)
     {
         return Iterator(lookup_with_hash(hash, move(predicate)));
     }
 
-    Iterator find(const T& value)
+    [[nodiscard]] Iterator find(T const& value)
     {
         return find(TraitsForT::hash(value), [&](auto& other) { return TraitsForT::equals(value, other); });
     }
 
     template<typename TUnaryPredicate>
-    ConstIterator find(unsigned hash, TUnaryPredicate predicate) const
+    [[nodiscard]] ConstIterator find(unsigned hash, TUnaryPredicate predicate) const
     {
         return ConstIterator(lookup_with_hash(hash, move(predicate)));
     }
 
-    ConstIterator find(const T& value) const
+    [[nodiscard]] ConstIterator find(T const& value) const
     {
         return find(TraitsForT::hash(value), [&](auto& other) { return TraitsForT::equals(value, other); });
     }
@@ -360,7 +360,7 @@ private:
         }
     }
 
-    static size_t size_in_bytes(size_t capacity)
+    [[nodiscard]] static size_t size_in_bytes(size_t capacity)
     {
         if constexpr (IsOrdered) {
             return sizeof(BucketType) * capacity;
@@ -406,7 +406,7 @@ private:
     }
 
     template<typename TUnaryPredicate>
-    BucketType* lookup_with_hash(unsigned hash, TUnaryPredicate predicate) const
+    [[nodiscard]] BucketType* lookup_with_hash(unsigned hash, TUnaryPredicate predicate) const
     {
         if (is_empty())
             return nullptr;
@@ -424,12 +424,12 @@ private:
         }
     }
 
-    const BucketType* lookup_for_reading(const T& value) const
+    [[nodiscard]] BucketType const* lookup_for_reading(T const& value) const
     {
         return lookup_with_hash(TraitsForT::hash(value), [&value](auto& entry) { return TraitsForT::equals(entry, value); });
     }
 
-    BucketType& lookup_for_writing(const T& value)
+    [[nodiscard]] BucketType& lookup_for_writing(T const& value)
     {
         if (should_grow())
             rehash(capacity() * 2);