QVector - add functions takeFirst and takeLast

This patch adds takeFirst and takeLast which are functions
that QList also has.

Change-Id: I761f90b529774edc8fa96e07c6fcf76226123b20
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 40 insertions, 3 deletions

diff --git a/src/corelib/tools/qvector.cpp b/src/corelib/tools/qvector.cpp
index 5ece011f0b..e72c1964a2 100644
--- a/src/corelib/tools/qvector.cpp
+++ b/src/corelib/tools/qvector.cpp
@@ -551,7 +551,7 @@
     the vector can be empty, call isEmpty() before calling this
     function.
 
-    \sa remove(), isEmpty()
+    \sa remove(), takeFirst(), isEmpty()
 */
 
 /*! \fn void QVector::removeLast()
@@ -561,9 +561,31 @@
     empty. If the vector can be empty, call isEmpty() before calling
     this function.
 
-    \sa remove(), removeFirst(), isEmpty()
+    \sa remove(), takeLast(), removeFirst(), isEmpty()
 */
 
+/*! \fn T QVector::takeFirst()
+
+    Removes the first item in the vector and returns it. This function
+    assumes the vector is not empty. To avoid failure, call isEmpty()
+    before calling this function.
+
+    \sa takeLast(), removeFirst()
+*/
+
+/*! \fn T QVector::takeLast()
+
+    Removes the last item in the list and returns it. This function
+    assumes the vector is not empty. To avoid failure, call isEmpty()
+    before calling this function.
+
+    If you don't use the return value, removeLast() is more
+    efficient.
+
+    \sa takeFirst(), removeLast()
+*/
+
+
 /*! \fn QVector &QVector::fill(const T &value, int size = -1)
 
     Assigns \a value to all items in the vector. If \a size is
diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index f6fe316a15..e2c28e4060 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -140,6 +140,8 @@ public:
     void remove(int i, int n);
     inline void removeFirst() { Q_ASSERT(!isEmpty()); erase(d->begin()); }
     inline void removeLast()  { Q_ASSERT(!isEmpty()); erase(d->end() - 1); }
+    inline T takeFirst() { Q_ASSERT(!isEmpty()); T r = first(); removeFirst(); return r; }
+    inline T takeLast()  { Q_ASSERT(!isEmpty()); T r = last(); removeLast(); return r; }
 
     QVector<T> &fill(const T &t, int size = -1);
 
diff --git a/tests/auto/corelib/tools/qvector/tst_qvector.cpp b/tests/auto/corelib/tools/qvector/tst_qvector.cpp
index 3acd5ddb10..99fbb9cf98 100644
--- a/tests/auto/corelib/tools/qvector/tst_qvector.cpp
+++ b/tests/auto/corelib/tools/qvector/tst_qvector.cpp
@@ -1410,11 +1410,12 @@ struct RemoveLastTestClass
 void tst_QVector::removeFirstLast() const
 {
     // pop_pack - pop_front
-    QVector<int> t;
+    QVector<int> t, t2;
     t.append(1);
     t.append(2);
     t.append(3);
     t.append(4);
+    t2 = t;
     t.pop_front();
     QCOMPARE(t.size(), 3);
     QCOMPARE(t.at(0), 2);
@@ -1423,6 +1424,18 @@ void tst_QVector::removeFirstLast() const
     QCOMPARE(t.at(0), 2);
     QCOMPARE(t.at(1), 3);
 
+    // takefirst - takeLast
+    int n1 = t2.takeLast();
+    QCOMPARE(t2.size(), 3);
+    QCOMPARE(n1, 4);
+    QCOMPARE(t2.at(0), 1);
+    QCOMPARE(t2.at(2), 3);
+    n1 = t2.takeFirst();
+    QCOMPARE(t2.size(), 2);
+    QCOMPARE(n1, 1);
+    QCOMPARE(t2.at(0), 2);
+    QCOMPARE(t2.at(1), 3);
+
     // remove first
     QVector<int> x, y;
     x.append(1);