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, 10 insertions, 0 deletions

diff --git a/src/corelib/serialization/qcbormap.h b/src/corelib/serialization/qcbormap.h
index 9499f46ace..89de3d6786 100644
--- a/src/corelib/serialization/qcbormap.h
+++ b/src/corelib/serialization/qcbormap.h
@@ -207,6 +207,14 @@ public:
     QCborValueRef operator[](const QString & key);
     QCborValueRef operator[](const QCborValue &key);
 
+    QCborValue take(qint64 key)
+    { iterator it = find(key); if (it != end()) return extract(it); return QCborValue(); }
+    QCborValue take(QLatin1String key)
+    { iterator it = find(key); if (it != end()) return extract(it); return QCborValue(); }
+    QCborValue take(const QString &key)
+    { iterator it = find(key); if (it != end()) return extract(it); return QCborValue(); }
+    QCborValue take(const QCborValue &key)
+    { iterator it = find(key); if (it != end()) return extract(it); return QCborValue(); }
     void remove(qint64 key)
     { iterator it = find(key); if (it != end()) erase(it); }
     void remove(QLatin1String key)
@@ -254,6 +262,8 @@ public:
     const_iterator cend() const { return constEnd(); }
     iterator erase(iterator it);
     iterator erase(const_iterator it) { return erase(iterator{ it.item.d, it.item.i }); }
+    QCborValue extract(iterator it);
+    QCborValue extract(const_iterator it) { return extract(iterator{ it.item.d, it.item.i }); }
     bool empty() const { return isEmpty(); }
 
     iterator find(qint64 key);