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| author | Marc Mutz <marc.mutz@kdab.com> | 2014-03-25 00:28:19 +0100 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@kdab.com> | 2014-08-24 13:42:42 +0200 |
| commit | e3e4fe79100162a9fc47b923fe23d1a296cd67d1 (patch) | |
| tree | f362b582bb229d4d036d87b093f474b168ab3eb1 /src/corelib/tools | |
| parent | b98381821900154276ce207799293a00a5f40f0e (diff) | |
Use std::vector range ctor in QVector::toStdVector()
There are three reasons to do so:
1. This could be more efficient, depending on the STL implementation.
2. By using QTypedArrayData iterators (T*) instead of QVector ones,
we actually invoke the non-templated range ctor of std::vector,
at least in the common case that std::vector<T>::const_iterator
is also const T*.
3. The change turns a former NRVO return into a RVO one, potentially
allowing more compilers to perform the copy elision.
Change-Id: I70b35aaeae70ba06a971a36b8b1b1da997e8094f
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Diffstat (limited to 'src/corelib/tools')
| -rw-r--r-- | src/corelib/tools/qvector.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h index f09f1a3c41..c92f43e1fc 100644 --- a/src/corelib/tools/qvector.h +++ b/src/corelib/tools/qvector.h @@ -256,7 +256,7 @@ public: static inline QVector<T> fromStdVector(const std::vector<T> &vector) { QVector<T> tmp; tmp.reserve(int(vector.size())); std::copy(vector.begin(), vector.end(), std::back_inserter(tmp)); return tmp; } inline std::vector<T> toStdVector() const - { std::vector<T> tmp; tmp.reserve(size()); std::copy(constBegin(), constEnd(), std::back_inserter(tmp)); return tmp; } + { return std::vector<T>(d->begin(), d->end()); } private: friend class QRegion; // Optimization for QRegion::rects() |