QDate(Time): add a addDuration method

To complement the existing addSecs / MSecs / etc., add a function
that takes any compatible std::chrono::duration.

QTime also features similar functions, but it's also "unique" in that
it uses modular arithmetic (it wraps around in case of "overflow").
I'm not so sure that adding durations to a QTime object therefore
makes sense, and I'm not doing it in this patch.

[ChangeLog][QtCore][QDate] Added addDuration().
[ChangeLog][QtCore][QDateTime] Added addDuration().

Change-Id: I02aa37ff024d7f56fa976dc8f4f73523bdba8d94
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 27 insertions, 14 deletions

diff --git a/tests/auto/corelib/time/qdate/tst_qdate.cpp b/tests/auto/corelib/time/qdate/tst_qdate.cpp
index 5d56eef559..25cf5d7c37 100644
--- a/tests/auto/corelib/time/qdate/tst_qdate.cpp
+++ b/tests/auto/corelib/time/qdate/tst_qdate.cpp
@@ -767,11 +767,19 @@ void tst_QDate::addDays()
     QFETCH( int, expectedDay );
 
     QDate dt( year, month, day );
-    dt = dt.addDays( amountToAdd );
+    QDate dt2 = dt.addDays( amountToAdd );
 
-    QCOMPARE( dt.year(), expectedYear );
-    QCOMPARE( dt.month(), expectedMonth );
-    QCOMPARE( dt.day(), expectedDay );
+    QCOMPARE( dt2.year(), expectedYear );
+    QCOMPARE( dt2.month(), expectedMonth );
+    QCOMPARE( dt2.day(), expectedDay );
+
+#if __cpp_lib_chrono >= 201907L
+    QDate dt3 = dt.addDuration( std::chrono::days( amountToAdd ) );
+
+    QCOMPARE( dt3.year(), expectedYear );
+    QCOMPARE( dt3.month(), expectedMonth );
+    QCOMPARE( dt3.day(), expectedDay );
+#endif
 }
 
 void tst_QDate::addDays_data()
diff --git a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
index 17f560b35c..334d308839 100644
--- a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
@@ -1524,16 +1524,21 @@ void tst_QDateTime::addMSecs()
     QFETCH(const qint64, nsecs);
     QFETCH(const QDateTime, result);
 
-    QDateTime test = dt.addMSecs(qint64(nsecs) * 1000);
-    if (!result.isValid()) {
-        QVERIFY(!test.isValid());
-    } else {
-        QCOMPARE(test, result);
-        QCOMPARE(test.timeSpec(), dt.timeSpec());
-        if (test.timeSpec() == Qt::OffsetFromUTC)
-            QCOMPARE(test.offsetFromUtc(), dt.offsetFromUtc());
-        QCOMPARE(result.addMSecs(qint64(-nsecs) * 1000), dt);
-    }
+    const auto verify = [&](const QDateTime &test) {
+        if (!result.isValid()) {
+            QVERIFY(!test.isValid());
+        } else {
+            QCOMPARE(test, result);
+            QCOMPARE(test.timeSpec(), dt.timeSpec());
+            if (test.timeSpec() == Qt::OffsetFromUTC)
+                QCOMPARE(test.offsetFromUtc(), dt.offsetFromUtc());
+            QCOMPARE(result.addMSecs(qint64(-nsecs) * 1000), dt);
+        }
+    };
+
+    verify(dt.addMSecs(qint64(nsecs) * 1000));
+    verify(dt.addDuration(std::chrono::seconds(nsecs)));
+    verify(dt.addDuration(std::chrono::milliseconds(nsecs * 1000)));
 }
 
 void tst_QDateTime::toTimeSpec_data()