Add qHash(QRegExp) and qHash(QRegularExpression)

QReg*Exp*s can be compared for equality,
so qHash should be overloaded, too.

There was a (poor) private implementation of qHash(QRegExpEngineKey)
already, which has now been replaced with a better one (the old one
didn't take into account all the fields that make up equality,
producing unnecessary collisions).

[ChangeLog][QtCore][QRegExp] Added qHash(QRegExp).
[ChangeLog][QtCore][QRegularExpression] Added qHash(QRegularExpression).

Change-Id: I1d22fbcc0508018a3f94b4c24571b13ba6e07df2
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

1 files changed, 25 insertions, 5 deletions

diff --git a/src/corelib/tools/qregexp.cpp b/src/corelib/tools/qregexp.cpp
index cd8c393d51..5aa9d54843 100644
--- a/src/corelib/tools/qregexp.cpp
+++ b/src/corelib/tools/qregexp.cpp
@@ -38,6 +38,7 @@
 #include "qcache.h"
 #include "qdatastream.h"
 #include "qdebug.h"
+#include "qhashfunctions.h"
 #include "qlist.h"
 #include "qmap.h"
 #include "qmutex.h"
@@ -882,6 +883,15 @@ static bool operator==(const QRegExpEngineKey &key1, const QRegExpEngineKey &key
            && key1.cs == key2.cs;
 }
 
+static uint qHash(const QRegExpEngineKey &key, uint seed = 0) Q_DECL_NOTHROW
+{
+    QtPrivate::QHashCombine hash;
+    seed = hash(seed, key.pattern);
+    seed = hash(seed, key.patternSyntax);
+    seed = hash(seed, key.cs);
+    return seed;
+}
+
 class QRegExpEngine;
 
 //Q_DECLARE_TYPEINFO(QVector<int>, Q_MOVABLE_TYPE);
@@ -3807,11 +3817,6 @@ struct QRegExpPrivate
 };
 
 #if !defined(QT_NO_REGEXP_OPTIM)
-uint qHash(const QRegExpEngineKey &key, uint seed = 0) Q_DECL_NOTHROW
-{
-    return qHash(key.pattern, seed);
-}
-
 typedef QCache<QRegExpEngineKey, QRegExpEngine> EngineCache;
 Q_GLOBAL_STATIC(EngineCache, globalEngineCache)
 static QBasicMutex globalEngineCacheMutex;
@@ -4033,6 +4038,21 @@ bool QRegExp::operator==(const QRegExp &rx) const
 }
 
 /*!
+    \since 5.6
+    \relates QRegExp
+
+    Returns the hash value for \a key, using
+    \a seed to seed the calculation.
+*/
+uint qHash(const QRegExp &key, uint seed) Q_DECL_NOTHROW
+{
+    QtPrivate::QHashCombine hash;
+    seed = hash(seed, key.priv->engineKey);
+    seed = hash(seed, key.priv->minimal);
+    return seed;
+}
+
+/*!
     \fn bool QRegExp::operator!=(const QRegExp &rx) const
 
     Returns \c true if this regular expression is not equal to \a rx;