QCborArray & Map: implement efficient take() / extract()

Questions:
 1) should QCborMap::extract return value_type (a pair) instead of just
    the value?
 2) should the both return the iterator to the next element too, like
    erase()?

Change-Id: I052407b777ec43f78378fffd15302a9c14468db3
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/corelib/serialization/qcborarray.h b/src/corelib/serialization/qcborarray.h
index f10fcac2cb..0be362480c 100644
--- a/src/corelib/serialization/qcborarray.h
+++ b/src/corelib/serialization/qcborarray.h
@@ -192,8 +192,9 @@ public:
     void insert(qsizetype i, const QCborValue &value);
     void prepend(const QCborValue &value) { insert(0, value); }
     void append(const QCborValue &value) { insert(-1, value); }
+    QCborValue extract(Iterator it);
     void removeAt(qsizetype i);
-    QCborValue takeAt(qsizetype i) { QCborValue v = at(i); removeAt(i); return v; }
+    QCborValue takeAt(qsizetype i) { Q_ASSERT(i < size()); return extract(begin() + i); }
     void removeFirst() { removeAt(0); }
     void removeLast() { removeAt(size() - 1); }
     QCborValue takeFirst() { return takeAt(0); }