Avoid expensive iterator calculations in append()

Avoid moving data inside the array to create free
space at one end. This is a performance bottleneck,
as it required quite a lot of calculations for every
insert. Rather reallocate and grow in this case,
so we only need to do expensive work when we reallocate
the array.

Change-Id: Ifc955fbcf9967c3b66aa2600e0627aac15f0c917
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 46c2fd3f66..66a99d4e43 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -1059,7 +1059,7 @@ private:
     static const char16_t _empty;
 
     void reallocData(qsizetype alloc, Data::ArrayOptions options);
-    void reallocGrowData(qsizetype alloc, Data::ArrayOptions options);
+    void reallocGrowData(qsizetype n);
     static int compare_helper(const QChar *data1, qsizetype length1,
                               const QChar *data2, qsizetype length2,
                               Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;