QMap/QHash: s/QPair/std::pair/

Also port from qMakePair to just braced initialization using CTAD.

Task-number: QTBUG-115841
Change-Id: Ib0ad55d7110521e34004dc9050022f9c0046722e
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
(cherry picked from commit 0d1575828015f99a495af84fb7de3746c7f61717)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/tools/qhash.cpp

@@ -1783,8 +1783,8 @@ size_t qHash(long double key, size_t seed) noexcept
 
     Constructs a hash with a copy of each of the elements in the iterator range
     [\a begin, \a end). Either the elements iterated by the range must be
-    objects with \c{first} and \c{second} data members (like \c{QPair},
+    objects with \c{first} and \c{second} data members (like \c{std::pair}),
-    \c{std::pair}, etc.) convertible to \c Key and to \c T respectively; or the
+    convertible to \c Key and to \c T respectively; or the
     iterators must have \c{key()} and \c{value()} member functions, returning a
     key convertible to \c Key and a value convertible to \c T respectively.
 */
@@ -2362,7 +2362,7 @@ size_t qHash(long double key, size_t seed) noexcept
     returns \c false.
 */
 
-/*! \fn template <class Key, class T> QPair<iterator, iterator> QMultiHash<Key, T>::equal_range(const Key &key)
+/*! \fn template <class Key, class T> std::pair<iterator, iterator> QMultiHash<Key, T>::equal_range(const Key &key)
     \since 5.7
 
     Returns a pair of iterators delimiting the range of values \c{[first, second)}, that
@@ -2370,7 +2370,7 @@ size_t qHash(long double key, size_t seed) noexcept
 */
 
 /*!
-    \fn template <class Key, class T> QPair<const_iterator, const_iterator> QMultiHash<Key, T>::equal_range(const Key &key) const
+    \fn template <class Key, class T> std::pair<const_iterator, const_iterator> QMultiHash<Key, T>::equal_range(const Key &key) const
     \overload
     \since 5.7
 */
@@ -2955,8 +2955,8 @@ size_t qHash(long double key, size_t seed) noexcept
 
     Constructs a multi-hash with a copy of each of the elements in the iterator range
     [\a begin, \a end). Either the elements iterated by the range must be
-    objects with \c{first} and \c{second} data members (like \c{QPair},
+    objects with \c{first} and \c{second} data members (like \c{std::pair}),
-    \c{std::pair}, etc.) convertible to \c Key and to \c T respectively; or the
+    convertible to \c Key and to \c T respectively; or the
     iterators must have \c{key()} and \c{value()} member functions, returning a
     key convertible to \c Key and a value convertible to \c T respectively.
 */

src/corelib/tools/qhash.h

@@ -1234,22 +1234,22 @@ public:
         return i;
     }
 
-    QPair<iterator, iterator> equal_range(const Key &key)
+    std::pair<iterator, iterator> equal_range(const Key &key)
     {
         auto first = find(key);
         auto second = first;
         if (second != iterator())
             ++second;
-        return qMakePair(first, second);
+        return {first, second};
     }
 
-    QPair<const_iterator, const_iterator> equal_range(const Key &key) const noexcept
+    std::pair<const_iterator, const_iterator> equal_range(const Key &key) const noexcept
     {
         auto first = find(key);
         auto second = first;
         if (second != iterator())
             ++second;
-        return qMakePair(first, second);
+        return {first, second};
     }
 
     typedef iterator Iterator;
@@ -2125,26 +2125,26 @@ public:
         return *this;
     }
 
-    QPair<iterator, iterator> equal_range(const Key &key)
+    std::pair<iterator, iterator> equal_range(const Key &key)
     {
         const auto copy = isDetached() ? QMultiHash() : *this; // keep 'key' alive across the detach
         detach();
         auto pair = std::as_const(*this).equal_range(key);
-        return qMakePair(iterator(pair.first.i), iterator(pair.second.i));
+        return {iterator(pair.first.i), iterator(pair.second.i)};
     }
 
-    QPair<const_iterator, const_iterator> equal_range(const Key &key) const noexcept
+    std::pair<const_iterator, const_iterator> equal_range(const Key &key) const noexcept
     {
         if (!d)
-            return qMakePair(end(), end());
+            return {end(), end()};
 
         auto bucket = d->findBucket(key);
         if (bucket.isUnused())
-            return qMakePair(end(), end());
+            return {end(), end()};
         auto it = bucket.toIterator(d);
         auto end = it;
         ++end;
-        return qMakePair(const_iterator(it), const_iterator(end));
+        return {const_iterator(it), const_iterator(end)};
     }
 
 private:

src/corelib/tools/qmap.h

@@ -762,7 +762,7 @@ public:
         return isEmpty();
     }
 
-    QPair<iterator, iterator> equal_range(const Key &akey)
+    std::pair<iterator, iterator> equal_range(const Key &akey)
     {
         const auto copy = d.isShared() ? *this : QMap(); // keep `key` alive across the detach
         detach();
@@ -770,7 +770,7 @@ public:
         return {iterator(result.first), iterator(result.second)};
     }
 
-    QPair<const_iterator, const_iterator> equal_range(const Key &akey) const
+    std::pair<const_iterator, const_iterator> equal_range(const Key &akey) const
     {
         if (!d)
             return {};
@@ -1492,7 +1492,7 @@ public:
     // STL compatibility
     inline bool empty() const { return isEmpty(); }
 
-    QPair<iterator, iterator> equal_range(const Key &akey)
+    std::pair<iterator, iterator> equal_range(const Key &akey)
     {
         const auto copy = d.isShared() ? *this : QMultiMap(); // keep `key` alive across the detach
         detach();
@@ -1500,7 +1500,7 @@ public:
         return {iterator(result.first), iterator(result.second)};
     }
 
-    QPair<const_iterator, const_iterator> equal_range(const Key &akey) const
+    std::pair<const_iterator, const_iterator> equal_range(const Key &akey) const
     {
         if (!d)
             return {};

src/corelib/tools/qmap.qdoc

@@ -818,14 +818,14 @@
 */
 
 /*!
-  \fn template <class Key, class T> QPair<typename QMap<Key, T>::iterator, typename QMap<Key, T>::iterator> QMap<Key, T>::equal_range(const Key &key)
+  \fn template <class Key, class T> std::pair<typename QMap<Key, T>::iterator, typename QMap<Key, T>::iterator> QMap<Key, T>::equal_range(const Key &key)
 
   Returns a pair of iterators delimiting the range of values \c{[first, second)}, that
   are stored under \a key.
 */
 
 /*!
-    \fn template <class Key, class T> QPair<typename QMap<Key, T>::const_iterator, typename QMap<Key, T>::const_iterator> QMap<Key, T>::equal_range(const Key &key) const
+    \fn template <class Key, class T> std::pair<typename QMap<Key, T>::const_iterator, typename QMap<Key, T>::const_iterator> QMap<Key, T>::equal_range(const Key &key) const
     \overload
     \since 5.6
 */

src/corelib/tools/qmultimap.qdoc

@@ -934,14 +934,14 @@
 */
 
 /*!
-  \fn template <class Key, class T> QPair<typename QMultiMap<Key, T>::iterator, typename QMultiMap<Key, T>::iterator> QMultiMap<Key, T>::equal_range(const Key &key)
+  \fn template <class Key, class T> std::pair<typename QMultiMap<Key, T>::iterator, typename QMultiMap<Key, T>::iterator> QMultiMap<Key, T>::equal_range(const Key &key)
 
   Returns a pair of iterators delimiting the range of values \c{[first, second)}, that
   are stored under \a key.
 */
 
 /*!
-    \fn template <class Key, class T> QPair<typename QMultiMap<Key, T>::const_iterator, typename QMultiMap<Key, T>::const_iterator> QMultiMap<Key, T>::equal_range(const Key &key) const
+    \fn template <class Key, class T> std::pair<typename QMultiMap<Key, T>::const_iterator, typename QMultiMap<Key, T>::const_iterator> QMultiMap<Key, T>::equal_range(const Key &key) const
     \overload
     \since 5.6
 */