QVector: add removeOne(), removeAll() for QList compatibility

Eases migration from QList to QVector.

[ChangeLog][QtCore][QVector] Added removeOne(), removeAll() for
QList compatibility.

Change-Id: I4211afb2e077c187d0a39f0ac4528f0c66721fb3
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

src/corelib/tools/qvector.cpp

@@ -576,6 +576,28 @@
     \sa remove(), QList::removeAt()
 */
 
+/*! \fn int QVector::removeAll(const T &t)
+    \since 5.4
+
+    Removes all elements that compare equal to \a t from the
+    vector. Returns the number of elements removed, if any.
+
+    Provided for compatibility with QList.
+
+    \sa removeOne(), QList::removeAll()
+*/
+
+/*! \fn bool QVector::removeOne(const T &t)
+    \since 5.4
+
+    Removes the first element that compares equal to \a t from the
+    vector. Returns whether an element was, in fact, removed.
+
+    Provided for compatibility with QList.
+
+    \sa removeAll(), QList::removeOne()
+*/
+
 /*! \fn int QVector::length() const
     \since 5.2
 

src/corelib/tools/qvector.h

@@ -154,6 +154,24 @@ public:
 
     // QList compatibility
     void removeAt(int i) { remove(i); }
+    int removeAll(const T &t)
+    {
+        const const_iterator ce = this->cend(), cit = std::find(this->cbegin(), ce, t);
+        if (cit == ce)
+            return 0;
+        const iterator e = end(), it = std::remove(c2m(cit), e, t);
+        const int result = std::distance(it, e);
+        erase(it, e);
+        return result;
+    }
+    bool removeOne(const T &t)
+    {
+        const int i = indexOf(t);
+        if (i < 0)
+            return false;
+        remove(i);
+        return true;
+    }
     int length() const { return size(); }
     T takeAt(int i) { T t = at(i); remove(i); return t; }
 
@@ -250,6 +268,7 @@ private:
     {
         return (i <= d->end()) && (d->begin() <= i);
     }
+    iterator c2m(const_iterator it) { return begin() + (it - cbegin()); }
     class AlignmentDummy { Data header; T array[1]; };
 };
 

tests/auto/corelib/tools/qvector/tst_qvector.cpp

@@ -1423,13 +1423,28 @@ void tst_QVector::remove() const
     T val1 = SimpleValue<T>::at(1);
     T val2 = SimpleValue<T>::at(2);
     T val3 = SimpleValue<T>::at(3);
+    T val4 = SimpleValue<T>::at(4);
+    myvec << val1 << val2 << val3;
+    myvec << val1 << val2 << val3;
     myvec << val1 << val2 << val3;
     // remove middle
     myvec.remove(1);
-    QCOMPARE(myvec, QVector<T>() << val1 << val3);
+    QCOMPARE(myvec, QVector<T>() << val1 << val3  << val1 << val2 << val3  << val1 << val2 << val3);
+
+    // removeOne()
+    QVERIFY(!myvec.removeOne(val4));
+    QVERIFY(myvec.removeOne(val2));
+    QCOMPARE(myvec, QVector<T>() << val1 << val3  << val1 << val3  << val1 << val2 << val3);
+
+    // removeAll()
+    QCOMPARE(myvec.removeAll(val4), 0);
+    QCOMPARE(myvec.removeAll(val1), 3);
+    QCOMPARE(myvec, QVector<T>() << val3  << val3  << val2 << val3);
+    QCOMPARE(myvec.removeAll(val2), 1);
+    QCOMPARE(myvec, QVector<T>() << val3  << val3  << val3);
 
     // remove rest
-    myvec.remove(0, 2);
+    myvec.remove(0, 3);
     QCOMPARE(myvec, QVector<T>());
 }