QCollatorSortKey: add some std::move

All implementations of QCollator::sortKey() can benefit from
moving their CollatorKeyType into the QCollatorSortKeyPrivate
on construction.

So make the QCollatorSortKeyPrivate ctor a perfect forwarder
for its m_key member, and add std::move() calls where they
were missing (in all but one case, lvalues were passed).

Make the ctor explicit, as it should have been from the
beginning.

Change-Id: I2a1cdda5fd23990ace019b963df895c621a1fa85
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/corelib/tools/qcollator_icu.cpp

@@ -145,7 +145,7 @@ QCollatorSortKey QCollator::sortKey(const QString &string) const
                                    string.size(), (uint8_t *)result.data(), result.size());
         }
         result.truncate(size);
-        return QCollatorSortKey(new QCollatorSortKeyPrivate(result));
+        return QCollatorSortKey(new QCollatorSortKeyPrivate(std::move(result)));
     }
 
     return QCollatorSortKey(new QCollatorSortKeyPrivate(QByteArray()));

src/corelib/tools/qcollator_macx.cpp

@@ -131,7 +131,7 @@ QCollatorSortKey QCollator::sortKey(const QString &string) const
                           ret.size(), &actualSize, ret.data());
     }
     ret[actualSize] = 0;
-    return QCollatorSortKey(new QCollatorSortKeyPrivate(ret));
+    return QCollatorSortKey(new QCollatorSortKeyPrivate(std::move(ret)));
 }
 
 int QCollatorSortKey::compare(const QCollatorSortKey &key) const

src/corelib/tools/qcollator_p.h

@@ -131,9 +131,10 @@ class QCollatorSortKeyPrivate : public QSharedData
 {
     friend class QCollator;
 public:
-    QCollatorSortKeyPrivate(const CollatorKeyType &key)
+    template <typename...T>
+    explicit QCollatorSortKeyPrivate(T &&...args)
         : QSharedData()
-        , m_key(key)
+        , m_key(std::forward<T>(args)...)
     {
     }
 

src/corelib/tools/qcollator_posix.cpp

@@ -110,7 +110,7 @@ QCollatorSortKey QCollator::sortKey(const QString &string) const
     }
     result.resize(size+1);
     result[size] = 0;
-    return QCollatorSortKey(new QCollatorSortKeyPrivate(result));
+    return QCollatorSortKey(new QCollatorSortKeyPrivate(std::move(result)));
 }
 
 int QCollatorSortKey::compare(const QCollatorSortKey &otherKey) const

src/corelib/tools/qcollator_win.cpp

@@ -147,7 +147,7 @@ QCollatorSortKey QCollator::sortKey(const QString &string) const
     if (finalSize == 0) {
         qWarning() << "there were problems when generating the ::sortKey by LCMapStringW with error:" << GetLastError();
     }
-    return QCollatorSortKey(new QCollatorSortKeyPrivate(ret));
+    return QCollatorSortKey(new QCollatorSortKeyPrivate(std::move(ret)));
 }
 
 int QCollatorSortKey::compare(const QCollatorSortKey &otherKey) const