WTF: Add support for std::initializer_list in HashSet.

third_party/WebKit/Source/wtf/HashSet.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
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  */
 
 #ifndef WTF_HashSet_h
 #define WTF_HashSet_h
 
 #include "wtf/HashTable.h"
 #include "wtf/allocator/PartitionAllocator.h"
+#include <initializer_list>
 
 namespace WTF {
 
 struct IdentityExtractor;
 
 // Note: empty or deleted values are not allowed, using them may lead to
 // undefined behavior.  For pointer valuess this means that null pointers are
 // not allowed unless you supply custom traits.
 template <
     typename ValueArg,
@@ skipping 12 matching lines @@
 
 private:
     typedef HashTable<ValueType, ValueType, IdentityExtractor,
         HashFunctions, ValueTraits, ValueTraits, Allocator> HashTableType;
 
 public:
     typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> iterator;
     typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> const_iterator;
     typedef typename HashTableType::AddResult AddResult;
 
+    HashSet() = default;
+    HashSet(const HashSet&) = default;
+    HashSet& operator=(const HashSet&) = default;
+    HashSet(HashSet&&) = default;
+    HashSet& operator=(HashSet&&) = default;
+
+    HashSet(std::initializer_list<ValueType> elements);
+    HashSet& operator=(std::initializer_list<ValueType> elements);
+
     void swap(HashSet& ref)
     {
         m_impl.swap(ref.m_impl);
     }
 
     unsigned size() const;
     unsigned capacity() const;
     bool isEmpty() const;
 
     void reserveCapacityForSize(unsigned size)
@@ skipping 56 matching lines @@
 struct HashSetTranslatorAdapter {
     STATIC_ONLY(HashSetTranslatorAdapter);
     template <typename T> static unsigned hash(const T& key) { return Translator::hash(key); }
     template <typename T, typename U> static bool equal(const T& a, const U& b) { return Translator::equal(a, b); }
     template <typename T, typename U, typename V> static void translate(T& location, U&& key, const V&, unsigned hashCode)
     {
         Translator::translate(location, std::forward<U>(key), hashCode);
     }
 };
 
+template <typename Value, typename HashFunctions, typename Traits, typename Allocator>
+HashSet<Value, HashFunctions, Traits, Allocator>::HashSet(std::initializer_list<ValueType> elements)
+{

[tzik, 2016/05/19 08:59:57]

Can we reserveCapacity here?

[Yuta Kitamura, 2016/05/19 09:04:21]

Done.

+    for (const auto& element : elements)
+        add(element);
+}
+
+template <typename Value, typename HashFunctions, typename Traits, typename Allocator>
+auto HashSet<Value, HashFunctions, Traits, Allocator>::operator=(std::initializer_list<ValueType> elements) -> HashSet&
+{
+    clear();
+    for (const auto& element : elements)
+        add(element);
+    return *this;
+}
+
 template <typename T, typename U, typename V, typename W>
 inline unsigned HashSet<T, U, V, W>::size() const
 {
     return m_impl.size();
 }
 
 template <typename T, typename U, typename V, typename W>
 inline unsigned HashSet<T, U, V, W>::capacity() const
 {
     return m_impl.capacity();
@@ skipping 117 matching lines @@
     iterator end = collection.end();
     for (unsigned i = 0; it != end; ++it, ++i)
         vector[i] = *it;
 }
 
 } // namespace WTF
 
 using WTF::HashSet;
 
 #endif // WTF_HashSet_h