Write qHash functions for QDate, QTime and QDateTime.

These functions didn't exist - this patch implements them.

Task-number: QTBUG-23079
Change-Id: I9eb6e238531d5cda878f5f2cdd27bab30aa60669
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 41 insertions, 0 deletions

diff --git a/src/corelib/tools/qdatetime.cpp b/src/corelib/tools/qdatetime.cpp
index 6c3836e0dc..4c3baa30ce 100644
--- a/src/corelib/tools/qdatetime.cpp
+++ b/src/corelib/tools/qdatetime.cpp
@@ -4067,6 +4067,43 @@ QDebug operator<<(QDebug dbg, const QDateTime &date)
 }
 #endif
 
+/*! \fn uint qHash(const QDateTime &key, uint seed = 0)
+    \relates QHash
+    \since 5.0
+
+    Returns the hash value for the \a key, using \a seed to seed the calculation.
+*/
+uint qHash(const QDateTime &key, uint seed)
+{
+    // Use to toMSecsSinceEpoch instead of individual qHash functions for
+    // QDate/QTime/spec/offset because QDateTime::operator== converts both arguments
+    // to the same timezone. If we don't, qHash would return different hashes for
+    // two QDateTimes that are equivalent once converted to the same timezone.
+    return qHash(key.toMSecsSinceEpoch(), seed);
+}
+
+/*! \fn uint qHash(const QDate &key, uint seed = 0)
+    \relates QHash
+    \since 5.0
+
+    Returns the hash value for the \a key, using \a seed to seed the calculation.
+*/
+uint qHash(const QDate &key, uint seed)
+{
+    return qHash(key.toJulianDay(), seed);
+}
+
+/*! \fn uint qHash(const QTime &key, uint seed = 0)
+    \relates QHash
+    \since 5.0
+
+    Returns the hash value for the \a key, using \a seed to seed the calculation.
+*/
+uint qHash(const QTime &key, uint seed)
+{
+    return QTime(0, 0, 0, 0).msecsTo(key) ^ seed;
+}
+
 #ifndef QT_BOOTSTRAPPED
 
 /*!
diff --git a/src/corelib/tools/qdatetime.h b/src/corelib/tools/qdatetime.h
index 83c5ed8c2e..6880b7bad7 100644
--- a/src/corelib/tools/qdatetime.h
+++ b/src/corelib/tools/qdatetime.h
@@ -288,6 +288,10 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QTime &);
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QDateTime &);
 #endif
 
+Q_CORE_EXPORT uint qHash(const QDateTime &key, uint seed = 0);
+Q_CORE_EXPORT uint qHash(const QDate &key, uint seed = 0);
+Q_CORE_EXPORT uint qHash(const QTime &key, uint seed = 0);
+
 QT_END_NAMESPACE
 
 QT_END_HEADER