QVersionNumber: add fromString(QStringView/QLatin1String) overloads

The parsing code anyway operated on a QByteArray created from
toLatin1(), so expose this to the user by providing a QLatin1String
overload.

Also provide a QStringView overload, since we can. Port one user (in
qmake) to the new overload.

[ChangeLog][QtCore][QVersionNumber] Added QStringView and
QLatin1String overloads of fromString().

Change-Id: Idbff44c3997f5cfa86ea1bce8b3da4b700a3d9cc
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

qmake/library/qmakebuiltins.cpp

@@ -1569,7 +1569,7 @@ QMakeEvaluator::VisitReturn QMakeEvaluator::evaluateBuiltinConditional(
             return ReturnFalse;
         }
         const QVersionNumber lvn = QVersionNumber::fromString(values(args.at(0).toKey()).join('.'));
-        const QVersionNumber rvn = QVersionNumber::fromString(args.at(1).toQString());
+        const QVersionNumber rvn = QVersionNumber::fromString(args.at(1).toQStringView());
         if (func_t == T_VERSION_AT_LEAST)
             return returnBool(lvn >= rvn);
         return returnBool(lvn <= rvn);

src/corelib/doc/snippets/qversionnumber/main.cpp

@@ -95,6 +95,14 @@ void QObject::parse()
     // version is 5.4.0
     // suffixIndex is 5
     //! [3]
+
+    //! [3-latin-1]
+    QLatin1String string("5.4.0-alpha");
+    int suffixIndex;
+    auto version = QVersionNumber::fromString(string, &suffixIndex);
+    // version is 5.4.0
+    // suffixIndex is 5
+    //! [3-latin-1]
 }
 
 void Object::equivalent()

src/corelib/tools/qversionnumber.cpp

@@ -406,10 +406,8 @@ QString QVersionNumber::toString() const
     return version;
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
-    \fn QVersionNumber QVersionNumber::fromString(const QString &string,
-                                                  int *suffixIndex)
-
     Constructs a QVersionNumber from a specially formatted \a string of
     non-negative decimal numbers delimited by '.'.
 
@@ -422,15 +420,54 @@ QString QVersionNumber::toString() const
     \sa isNull()
 */
 QVersionNumber QVersionNumber::fromString(const QString &string, int *suffixIndex)
+{
+    return fromString(QLatin1String(string.toLatin1()), suffixIndex);
+}
+#endif
+
+/*!
+    \since 5.10
+    \overload
+
+    Constructs a QVersionNumber from a specially formatted \a string of
+    non-negative decimal numbers delimited by '.'.
+
+    Once the numerical segments have been parsed, the remainder of the string
+    is considered to be the suffix string.  The start index of that string will be
+    stored in \a suffixIndex if it is not null.
+
+    \snippet qversionnumber/main.cpp 3
+
+    \sa isNull()
+*/
+QVersionNumber QVersionNumber::fromString(QStringView string, int *suffixIndex)
+{
+    return fromString(QLatin1String(string.toLatin1()), suffixIndex);
+}
+
+/*!
+    \since 5.10
+    \overload
+
+    Constructs a QVersionNumber from a specially formatted \a string of
+    non-negative decimal numbers delimited by '.'.
+
+    Once the numerical segments have been parsed, the remainder of the string
+    is considered to be the suffix string.  The start index of that string will be
+    stored in \a suffixIndex if it is not null.
+
+    \snippet qversionnumber/main.cpp 3-latin1-1
+
+    \sa isNull()
+*/
+QVersionNumber QVersionNumber::fromString(QLatin1String string, int *suffixIndex)
 {
     QVector<int> seg;
 
-    const QByteArray cString(string.toLatin1());
-
-    const char *start = cString.constData();
+    const char *start = string.begin();
     const char *end = start;
     const char *lastGoodEnd = start;
-    const char *endOfString = cString.constData() + cString.size();
+    const char *endOfString = string.end();
 
     do {
         bool ok = false;
@@ -443,7 +480,7 @@ QVersionNumber QVersionNumber::fromString(const QString &string, int *suffixInde
     } while (start < endOfString && (end < endOfString && *end == '.'));
 
     if (suffixIndex)
-        *suffixIndex = int(lastGoodEnd - cString.constData());
+        *suffixIndex = int(lastGoodEnd - string.begin());
 
     return QVersionNumber(qMove(seg));
 }

src/corelib/tools/qversionnumber.h

@@ -280,7 +280,11 @@ public:
     Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber commonPrefix(const QVersionNumber &v1, const QVersionNumber &v2) Q_REQUIRED_RESULT;
 
     Q_CORE_EXPORT QString toString() const Q_REQUIRED_RESULT;
+#if QT_STRINGVIEW_LEVEL < 2
     Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(const QString &string, int *suffixIndex = Q_NULLPTR) Q_REQUIRED_RESULT;
+#endif
+    Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QLatin1String string, int *suffixIndex = nullptr) Q_REQUIRED_RESULT;
+    Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber fromString(QStringView string, int *suffixIndex = nullptr) Q_REQUIRED_RESULT;
 
 private:
 #ifndef QT_NO_DATASTREAM

tests/auto/corelib/tools/qversionnumber/tst_qversionnumber.cpp

@@ -513,6 +513,14 @@ void tst_QVersionNumber::fromString()
     QCOMPARE(QVersionNumber::fromString(constructionString), expectedVersion);
     QCOMPARE(QVersionNumber::fromString(constructionString, &index), expectedVersion);
     QCOMPARE(index, suffixIndex);
+
+    QCOMPARE(QVersionNumber::fromString(QStringView(constructionString)), expectedVersion);
+    QCOMPARE(QVersionNumber::fromString(QStringView(constructionString), &index), expectedVersion);
+    QCOMPARE(index, suffixIndex);
+
+    QCOMPARE(QVersionNumber::fromString(QLatin1String(constructionString.toLatin1())), expectedVersion);
+    QCOMPARE(QVersionNumber::fromString(QLatin1String(constructionString.toLatin1()), &index), expectedVersion);
+    QCOMPARE(index, suffixIndex);
 }
 
 void tst_QVersionNumber::toString_data()