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, 18 insertions, 1 deletions

diff --git a/src/corelib/serialization/qcborarray.cpp b/src/corelib/serialization/qcborarray.cpp
index 020841d604..a1b0d1573c 100644
--- a/src/corelib/serialization/qcborarray.cpp
+++ b/src/corelib/serialization/qcborarray.cpp
@@ -42,6 +42,8 @@
 
 QT_BEGIN_NAMESPACE
 
+using namespace QtCbor;
+
 /*!
     \class QCborArray
     \inmodule QtCore
@@ -300,7 +302,7 @@ QCborValue QCborArray::at(qsizetype i) const
     must have at least \a i elements before the insertion.
 
     \sa at(), operator[](), first(), last(), prepend(), append(),
-        removeAt(), takeAt()
+        removeAt(), takeAt(), extract()
  */
 void QCborArray::insert(qsizetype i, const QCborValue &value)
 {
@@ -312,6 +314,21 @@ void QCborArray::insert(qsizetype i, const QCborValue &value)
 }
 
 /*!
+    Extracts a value from the array at the position indicated by iterator \a it
+    and returns the value so extracted.
+
+    \sa insert(), erase(), takeAt(), removeAt()
+ */
+QCborValue QCborArray::extract(iterator it)
+{
+    detach();
+
+    QCborValue v = d->extractAt(it.item.i);
+    d->removeAt(it.item.i);
+    return v;
+}
+
+/*!
     \fn void QCborArray::prepend(const QCborValue &value)
 
     Prepends \a value into the array before any other elements it may already