Introduce default ctors for QRegularExpressionMatch(Iterator)

This allows to put them in containers, and to enable subsequent
features for QString.

Change-Id: I3b3fe695ffe6930331ed9f670738376722e0fc36
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qregularexpression.cpp

@@ -1657,6 +1657,26 @@ QString QRegularExpression::escape(const QString &str)
     return result;
 }
 
+/*!
+    \since 5.1
+
+    Constructs a valid, empty QRegularExpressionMatch object. The regular
+    expression is set to a default-constructed one; the match type to
+    QRegularExpression::NoMatch and the match options to
+    QRegularExpression::NoMatchOption.
+
+    The object will report no match through the hasMatch() and the
+    hasPartialMatch() member functions.
+*/
+QRegularExpressionMatch::QRegularExpressionMatch()
+    : d(new QRegularExpressionMatchPrivate(QRegularExpression(),
+                                           QString(),
+                                           QRegularExpression::NoMatch,
+                                           QRegularExpression::NoMatchOption))
+{
+    d->isValid = true;
+}
+
 /*!
     Destroys the match result.
 */
@@ -2000,6 +2020,26 @@ QRegularExpressionMatchIterator::QRegularExpressionMatchIterator(QRegularExpress
 {
 }
 
+/*!
+    \since 5.1
+
+    Constructs an empty, valid QRegularExpressionMatchIterator object. The
+    regular expression is set to a default-constructed one; the match type to
+    QRegularExpression::NoMatch and the match options to
+    QRegularExpression::NoMatchOption.
+
+    Invoking the hasNext() member function on the constructed object will
+    return false, as the iterator is not iterating on a valid sequence of
+    matches.
+*/
+QRegularExpressionMatchIterator::QRegularExpressionMatchIterator()
+    : d(new QRegularExpressionMatchIteratorPrivate(QRegularExpression(),
+                                                   QRegularExpression::NoMatch,
+                                                   QRegularExpression::NoMatchOption,
+                                                   QRegularExpressionMatch()))
+{
+}
+
 /*!
     Destroys the QRegularExpressionMatchIterator object.
 */

src/corelib/tools/qregularexpression.h

@@ -154,6 +154,7 @@ struct QRegularExpressionMatchPrivate;
 class Q_CORE_EXPORT QRegularExpressionMatch
 {
 public:
+    QRegularExpressionMatch();
     ~QRegularExpressionMatch();
     QRegularExpressionMatch(const QRegularExpressionMatch &match);
     QRegularExpressionMatch &operator=(const QRegularExpressionMatch &match);
@@ -211,6 +212,7 @@ struct QRegularExpressionMatchIteratorPrivate;
 class Q_CORE_EXPORT QRegularExpressionMatchIterator
 {
 public:
+    QRegularExpressionMatchIterator();
     ~QRegularExpressionMatchIterator();
     QRegularExpressionMatchIterator(const QRegularExpressionMatchIterator &iterator);
     QRegularExpressionMatchIterator &operator=(const QRegularExpressionMatchIterator &iterator);

tests/auto/corelib/tools/qregularexpression/tst_qregularexpression.cpp

@@ -291,6 +291,31 @@ void tst_QRegularExpression::provideRegularExpressions()
                                                                      | QRegularExpression::InvertedGreedinessOption);
 }
 
+void tst_QRegularExpression::defaultConstructors()
+{
+    QRegularExpression re;
+    QCOMPARE(re.pattern(), QString());
+    QCOMPARE(re.patternOptions(), QRegularExpression::NoPatternOption);
+
+    QRegularExpressionMatch match;
+    QCOMPARE(match.regularExpression(), QRegularExpression());
+    QCOMPARE(match.regularExpression(), re);
+    QCOMPARE(match.matchType(), QRegularExpression::NoMatch);
+    QCOMPARE(match.matchOptions(), QRegularExpression::NoMatchOption);
+    QCOMPARE(match.hasMatch(), false);
+    QCOMPARE(match.hasPartialMatch(), false);
+    QCOMPARE(match.isValid(), true);
+    QCOMPARE(match.lastCapturedIndex(), -1);
+
+    QRegularExpressionMatchIterator iterator;
+    QCOMPARE(iterator.regularExpression(), QRegularExpression());
+    QCOMPARE(iterator.regularExpression(), re);
+    QCOMPARE(iterator.matchType(), QRegularExpression::NoMatch);
+    QCOMPARE(iterator.matchOptions(), QRegularExpression::NoMatchOption);
+    QCOMPARE(iterator.isValid(), true);
+    QCOMPARE(iterator.hasNext(), false);
+}
+
 void tst_QRegularExpression::gettersSetters_data()
 {
     provideRegularExpressions();

tests/auto/corelib/tools/qregularexpression/tst_qregularexpression.h

@@ -51,6 +51,7 @@ class tst_QRegularExpression : public QObject
     Q_OBJECT
 
 private slots:
+    void defaultConstructors();
     void gettersSetters_data();
     void gettersSetters();
     void escape_data();