add {QString,QByteArray,QList,QLinkedList,QHash,QMap,QVector}::isSharedWith()

these functions just compare the d pointers of two objects. this can be
used to verify the validity of cached data: you keep a copy of the
original data in your cache. consequently, any changes to the original
data must detach, so this function reflects whether the cached data is
still up-to-date.
of course, this is not thread safe, as the data might change right after
you check it, but that's a general problem of cache coherency which
needs to be handled further up the stack.

the functions are internal because the other detaching-related functions
are internal as well for reasons beyond me.

Reviewed-by: brad

1 files changed, 5 insertions, 0 deletions

diff --git a/src/corelib/tools/qbytearray.cpp b/src/corelib/tools/qbytearray.cpp
index bf9b6bd..e43c2b5 100644
--- a/src/corelib/tools/qbytearray.cpp
+++ b/src/corelib/tools/qbytearray.cpp
@@ -1048,6 +1048,11 @@ QByteArray &QByteArray::operator=(const char *str)
     \internal
 */
 
+/*! \fn bool QByteArray::isSharedWith(const QByteArray &other)
+
+    \internal
+*/
+
 /*! \fn char QByteArray::at(int i) const
 
     Returns the character at index position \a i in the byte array.