diff options
| author | Marc Mutz <marc.mutz@kdab.com> | 2012-02-18 11:45:45 +0100 |
|---|---|---|
| committer | Qt by Nokia <qt-info@nokia.com> | 2012-02-21 15:28:40 +0100 |
| commit | 3a8da4a4843d787e9bf12973bf1fcf4da793558d (patch) | |
| tree | 9a87d13388a5a83213df03af84531f6046d2375c | |
| parent | 6a6178702e8af97b943c728f1cb4ab20233835a2 (diff) | |
QEasingCurve: implement move constructor
The move constructor sets other.d_ptr to zero. This is safe, because
after being moved from, the object is left in a state in which it
can be safely destroyed (delete nullptr is a no-op).
It cannot meaningfully be used anymore (most members will crash with
a nullptr dereference), but in most cases, the moved-from object
cannot be accessed anyway (not a named object), and if a named object
is moved from, it must have been through explicit std::move(), as in
the test case.
The STL makes better guarantees (moved-from containers are .empty()),
but I don't think it's worth introducing a null state into
QEasingCurve just for supporting a use-case that should be
considered a bug anyway.
Change-Id: I4115b7386cdea6960507da6843a0d0196d8e4139
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
| -rw-r--r-- | src/corelib/tools/qeasingcurve.h | 1 | ||||
| -rw-r--r-- | tests/auto/corelib/tools/qeasingcurve/tst_qeasingcurve.cpp | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/src/corelib/tools/qeasingcurve.h b/src/corelib/tools/qeasingcurve.h index 33d7c6934e..64e4027fc4 100644 --- a/src/corelib/tools/qeasingcurve.h +++ b/src/corelib/tools/qeasingcurve.h @@ -84,6 +84,7 @@ public: QEasingCurve &operator=(const QEasingCurve &other); #ifdef Q_COMPILER_RVALUE_REFS + QEasingCurve(QEasingCurve &&other) : d_ptr(other.d_ptr) { other.d_ptr = 0; } QEasingCurve &operator=(QEasingCurve &&other) { qSwap(d_ptr, other.d_ptr); return *this; } #endif diff --git a/tests/auto/corelib/tools/qeasingcurve/tst_qeasingcurve.cpp b/tests/auto/corelib/tools/qeasingcurve/tst_qeasingcurve.cpp index 1d4e91dc00..40e3cd08b6 100644 --- a/tests/auto/corelib/tools/qeasingcurve/tst_qeasingcurve.cpp +++ b/tests/auto/corelib/tools/qeasingcurve/tst_qeasingcurve.cpp @@ -780,6 +780,12 @@ void tst_QEasingCurve::cpp11() #ifdef Q_COMPILER_RVALUE_REFS { QEasingCurve ec( QEasingCurve::InOutBack ); + QEasingCurve copy = std::move(ec); // move ctor + QCOMPARE( copy.type(), QEasingCurve::InOutBack ); + QVERIFY( *reinterpret_cast<void**>(&ec) == 0 ); + } + { + QEasingCurve ec( QEasingCurve::InOutBack ); QEasingCurve copy; const QEasingCurve::Type type = copy.type(); copy = std::move(ec); // move assignment op |