QMap: add const equal_range() overload

... to prevent detaching.

[ChangeLog][QtCore][QMap] Added const equal_range() overload.

Change-Id: I4b39abb8ad41ba6eaa8f9a9a74ed74ed10337dd3
Reviewed-by: Sérgio Martins <sergio.martins@kdab.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 50 insertions, 0 deletions

diff --git a/src/corelib/tools/qmap.cpp b/src/corelib/tools/qmap.cpp
index 1b7a8007cd..61e19252b3 100644
--- a/src/corelib/tools/qmap.cpp
+++ b/src/corelib/tools/qmap.cpp
@@ -1161,6 +1161,12 @@ void QMapDataBase::freeData(QMapDataBase *d)
   are stored under \a key.
 */
 
+/*!
+    \fn QPair<const_iterator, const_iterator> QMap::equal_range(const Key &key) const
+    \overload
+    \since 5.6
+*/
+
 
 /*! \class QMap::iterator
     \inmodule QtCore
diff --git a/src/corelib/tools/qmap.h b/src/corelib/tools/qmap.h
index 1f80e8f0f4..d92bb5ae60 100644
--- a/src/corelib/tools/qmap.h
+++ b/src/corelib/tools/qmap.h
@@ -557,6 +557,7 @@ public:
     typedef int size_type;
     inline bool empty() const { return isEmpty(); }
     QPair<iterator, iterator> equal_range(const Key &akey);
+    QPair<const_iterator, const_iterator> equal_range(const Key &akey) const;
 
 #ifdef Q_MAP_DEBUG
     void dump() const;
@@ -864,6 +865,15 @@ QPair<typename QMap<Key, T>::iterator, typename QMap<Key, T>::iterator> QMap<Key
     return QPair<iterator, iterator>(iterator(firstNode), iterator(lastNode));
 }
 
+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 &akey) const
+{
+    Node *firstNode, *lastNode;
+    d->nodeRange(akey, &firstNode, &lastNode);
+    return qMakePair(const_iterator(firstNode), const_iterator(lastNode));
+}
+
 #ifdef Q_MAP_DEBUG
 template <class Key, class T>
 void QMap<Key, T>::dump() const
diff --git a/tests/auto/corelib/tools/qmap/tst_qmap.cpp b/tests/auto/corelib/tools/qmap/tst_qmap.cpp
index 8560a2f18c..619f04337c 100644
--- a/tests/auto/corelib/tools/qmap/tst_qmap.cpp
+++ b/tests/auto/corelib/tools/qmap/tst_qmap.cpp
@@ -996,11 +996,16 @@ void tst_QMap::const_shared_null()
 void tst_QMap::equal_range()
 {
     QMap<int, QString> map;
+    const QMap<int, QString> &cmap = map;
 
     QPair<QMap<int, QString>::iterator, QMap<int, QString>::iterator> result = map.equal_range(0);
     QCOMPARE(result.first, map.end());
     QCOMPARE(result.second, map.end());
 
+    QPair<QMap<int, QString>::const_iterator, QMap<int, QString>::const_iterator> cresult = cmap.equal_range(0);
+    QCOMPARE(cresult.first, cmap.cend());
+    QCOMPARE(cresult.second, cmap.cend());
+
     map.insert(1, "one");
 
     result = map.equal_range(0);
@@ -1015,6 +1020,18 @@ void tst_QMap::equal_range()
     QCOMPARE(result.first, map.end());
     QCOMPARE(result.second, map.end());
 
+    cresult = cmap.equal_range(0);
+    QCOMPARE(cresult.first, cmap.find(1));
+    QCOMPARE(cresult.second, cmap.find(1));
+
+    cresult = cmap.equal_range(1);
+    QCOMPARE(cresult.first, cmap.find(1));
+    QCOMPARE(cresult.second, cmap.cend());
+
+    cresult = cmap.equal_range(2);
+    QCOMPARE(cresult.first, cmap.cend());
+    QCOMPARE(cresult.second, cmap.cend());
+
     for (int i = -10; i < 10; i += 2)
         map.insert(i, QString("%1").arg(i));
 
@@ -1030,11 +1047,28 @@ void tst_QMap::equal_range()
     QCOMPARE(result.first, map.find(2));
     QCOMPARE(result.second, map.find(4));
 
+    cresult = cmap.equal_range(0);
+    QCOMPARE(cresult.first, cmap.find(0));
+    QCOMPARE(cresult.second, cmap.find(1));
+
+    cresult = cmap.equal_range(1);
+    QCOMPARE(cresult.first, cmap.find(1));
+    QCOMPARE(cresult.second, cmap.find(2));
+
+    cresult = cmap.equal_range(2);
+    QCOMPARE(cresult.first, cmap.find(2));
+    QCOMPARE(cresult.second, cmap.find(4));
+
     map.insertMulti(1, "another one");
+
     result = map.equal_range(1);
     QCOMPARE(result.first, map.find(1));
     QCOMPARE(result.second, map.find(2));
 
+    cresult = cmap.equal_range(1);
+    QCOMPARE(cresult.first, cmap.find(1));
+    QCOMPARE(cresult.second, cmap.find(2));
+
     QCOMPARE(map.count(1), 2);
 }