From 2e3facf41971cc699b2ab9a62ff4da7654ba9497 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Mon, 18 Aug 2014 20:30:55 +0200
Subject: Micro-optimize QVector::count()

...by instantiating std::count() not with QVector::const_iterator, which is a
class, but with const T*, thus increasing the chance that the instantiation
can be shared with other instantiations in the executable. It might also enable
STL implementations to choose a hand-optimized version of the algorithm for C++
builtin types.

Change-Id: I93df4e58f76838d98b565f229c19e317774b7b4c
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
---
 src/corelib/tools/qvector.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index f26d61eb9c..cb4e193ffc 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -810,7 +810,9 @@ bool QVector<T>::contains(const T &t) const
 template <typename T>
 int QVector<T>::count(const T &t) const
 {
-    return int(std::count(cbegin(), cend(), t));
+    const T *b = d->begin();
+    const T *e = d->end();
+    return int(std::count(b, e, t));
 }
 
 template <typename T>
-- 
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