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| author | Marc Mutz <marc.mutz@kdab.com> | 2014-08-08 10:31:36 +0200 |
|---|---|---|
| committer | Oswald Buddenhagen <oswald.buddenhagen@digia.com> | 2014-08-09 09:06:16 +0200 |
| commit | e41b45f1aedf1b3fe0ca4b22226ccc23bc71ab7c (patch) | |
| tree | d64d54c7f865b19028548e8e6dceef760b9ae6a9 /tests | |
| parent | 31f2b7e5911f730245cf347924d1c839fc2832a4 (diff) | |
QPair: add constexpr liberally
On templates, adding constexpr makes a given instantiation constexpr
if it can be.
This turns qMakePair(0,0), say, into a compile-time constant.
The effects on existing code are small, but exist:
$ size lib/*{-baseline,-paircexp} | sort -nr
6516727 211192 2608 6730527 66b31f lib/libQt5Widgets.so.5.4.0-baseline
6516711 211192 2608 6730511 66b30f lib/libQt5Widgets.so.5.4.0-paircexp
5373720 44492 15976 5434188 52eb4c lib/libQt5Core.so.5.4.0-baseline
5373504 44492 15976 5433972 52ea74 lib/libQt5Core.so.5.4.0-paircexp
5107206 125072 6080 5238358 4fee56 lib/libQt5Gui.so.5.4.0-baseline
5107030 125072 6080 5238182 4feda6 lib/libQt5Gui.so.5.4.0-paircexp
1341290 30180 2600 1374070 14f776 lib/libQt5Network.so.5.4.0-baseline
1341210 30180 2600 1373990 14f726 lib/libQt5Network.so.5.4.0-paircexp
# no other libraries benefit
[ChangeLog][QtCore][QPair] Can now be used in C++11 constexpr contexts.
Change-Id: I3872e6aa33a7d02a168516f4dfa7119efcac8c40
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/auto/corelib/tools/qpair/tst_qpair.cpp | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/tests/auto/corelib/tools/qpair/tst_qpair.cpp b/tests/auto/corelib/tools/qpair/tst_qpair.cpp index 05031dbbf8..59b0ffb95e 100644 --- a/tests/auto/corelib/tools/qpair/tst_qpair.cpp +++ b/tests/auto/corelib/tools/qpair/tst_qpair.cpp @@ -42,12 +42,13 @@ #include <QtTest/QtTest> #include <QPair> +#include <QSize> class tst_QPair : public QObject { Q_OBJECT private Q_SLOTS: - void dummy() {} + void testConstexpr(); }; class C { char _[4]; }; @@ -101,5 +102,19 @@ Q_STATIC_ASSERT(!QTypeInfo<QPairPP>::isDummy ); Q_STATIC_ASSERT(!QTypeInfo<QPairPP>::isPointer); +void tst_QPair::testConstexpr() +{ + Q_CONSTEXPR QPair<int, double> pID = qMakePair(0, 0.0); + Q_UNUSED(pID); + + Q_CONSTEXPR QPair<double, double> pDD = qMakePair(0.0, 0.0); + Q_CONSTEXPR QPair<double, double> pDD2 = qMakePair(0, 0.0); // involes (rvalue) conversion ctor + Q_CONSTEXPR bool equal = pDD2 == pDD; + QVERIFY(equal); + + Q_CONSTEXPR QPair<QSize, int> pSI = qMakePair(QSize(4, 5), 6); + Q_UNUSED(pSI); +} + QTEST_APPLESS_MAIN(tst_QPair) #include "tst_qpair.moc" |