diff options
| -rw-r--r-- | src/corelib/global/qglobal.cpp | 8 | ||||
| -rw-r--r-- | tests/auto/corelib/global/qglobal/tst_qglobal.cpp | 56 |
2 files changed, 64 insertions, 0 deletions
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp index bcfc6ada2e..ee857d61ac 100644 --- a/src/corelib/global/qglobal.cpp +++ b/src/corelib/global/qglobal.cpp @@ -968,6 +968,8 @@ static_assert((std::is_same<qsizetype, qptrdiff>::value)); Rounds half away from zero (e.g. 0.5 -> 1, -0.5 -> -1). + \note This function does not guarantee correctness for high precisions. + Example: \snippet code/src_corelib_global_qglobal.cpp 11A @@ -980,6 +982,8 @@ static_assert((std::is_same<qsizetype, qptrdiff>::value)); Rounds half away from zero (e.g. 0.5f -> 1, -0.5f -> -1). + \note This function does not guarantee correctness for high precisions. + Example: \snippet code/src_corelib_global_qglobal.cpp 11B @@ -992,6 +996,8 @@ static_assert((std::is_same<qsizetype, qptrdiff>::value)); Rounds half away from zero (e.g. 0.5 -> 1, -0.5 -> -1). + \note This function does not guarantee correctness for high precisions. + Example: \snippet code/src_corelib_global_qglobal.cpp 12A @@ -1004,6 +1010,8 @@ static_assert((std::is_same<qsizetype, qptrdiff>::value)); Rounds half away from zero (e.g. 0.5f -> 1, -0.5f -> -1). + \note This function does not guarantee correctness for high precisions. + Example: \snippet code/src_corelib_global_qglobal.cpp 12B diff --git a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp index 3c4bd3840e..032567cd39 100644 --- a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp +++ b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp @@ -33,6 +33,8 @@ #include <QSysInfo> #include <QLatin1String> +#include <cmath> + class tst_QGlobal: public QObject { Q_OBJECT @@ -52,6 +54,10 @@ private slots: void buildAbiEndianness(); void testqOverload(); void testqMinMax(); + void qRoundFloats_data(); + void qRoundFloats(); + void qRoundDoubles_data(); + void qRoundDoubles(); }; extern "C" { // functions in qglobal.c @@ -602,6 +608,56 @@ void tst_QGlobal::testqMinMax() compare(qMax(quint64(1), ushort(2)), quint64(2)); } +void tst_QGlobal::qRoundFloats_data() +{ + QTest::addColumn<float>("actual"); + QTest::addColumn<float>("expected"); + + QTest::newRow("round half") << 0.5f << 1.0f; + QTest::newRow("round negative half") << -0.5f << -1.0f; + QTest::newRow("round negative") << -1.4f << -1.0f; + QTest::newRow("round largest representable float less than 0.5") << std::nextafter(0.5f, 0.0f) << 0.0f; +} + +void tst_QGlobal::qRoundFloats() { + QFETCH(float, actual); + QFETCH(float, expected); + + QEXPECT_FAIL("round largest representable float less than 0.5", + "We know qRound fails in this case, but decided that we value simplicity over correctness", + Continue); + QCOMPARE(qRound(actual), expected); + + QEXPECT_FAIL("round largest representable float less than 0.5", + "We know qRound fails in this case, but decided that we value simplicity over correctness", + Continue); + QCOMPARE(qRound64(actual), expected); +} + +void tst_QGlobal::qRoundDoubles_data() { + QTest::addColumn<double>("actual"); + QTest::addColumn<double>("expected"); + + QTest::newRow("round half") << 0.5 << 1.0; + QTest::newRow("round negative half") << -0.5 << -1.0; + QTest::newRow("round negative") << -1.4 << -1.0; + QTest::newRow("round largest representable double less than 0.5") << std::nextafter(0.5, 0.0) << 0.0; +} + +void tst_QGlobal::qRoundDoubles() { + QFETCH(double, actual); + QFETCH(double, expected); + + QEXPECT_FAIL("round largest representable double less than 0.5", + "We know qRound fails in this case, but decided that we value simplicity over correctness", + Continue); + QCOMPARE(qRound(actual), expected); + + QEXPECT_FAIL("round largest representable double less than 0.5", + "We know qRound fails in this case, but decided that we value simplicity over correctness", + Continue); + QCOMPARE(qRound64(actual), expected); +} QTEST_APPLESS_MAIN(tst_QGlobal) #include "tst_qglobal.moc" |