Add QHostAddress::isMulticast

This complements QHostAddress::isLoopback. The only missing check now is
for the "Any" address types, though operator== is quite fast nowadays.

Change-Id: Iee8cbc07c4434ce9b560ffff13cc2691e15014b6
Reviewed-by: Richard J. Moore <rich@kde.org>

2 files changed, 17 insertions, 0 deletions

diff --git a/src/network/kernel/qhostaddress.cpp b/src/network/kernel/qhostaddress.cpp
index 3d51ab4025..579567023e 100644
--- a/src/network/kernel/qhostaddress.cpp
+++ b/src/network/kernel/qhostaddress.cpp
@@ -1090,6 +1090,22 @@ bool QHostAddress::isLoopback() const
     return false;
 }
 
+/*!
+    \since 5.6
+
+    Returns \c true if the address is an IPv4 or IPv6 multicast address, \c
+    false otherwise.
+*/
+bool QHostAddress::isMulticast() const
+{
+    QT_ENSURE_PARSED(this);
+    if ((d->a & 0xF0000000) == 0xE0000000)
+        return true; // 224.0.0.0-239.255.255.255 (including v4-mapped IPv6 addresses)
+    if (d->protocol == QAbstractSocket::IPv6Protocol)
+        return d->a6.c[0] == 0xff;
+    return false;
+}
+
 #ifndef QT_NO_DEBUG_STREAM
 QDebug operator<<(QDebug d, const QHostAddress &address)
 {
diff --git a/src/network/kernel/qhostaddress.h b/src/network/kernel/qhostaddress.h
index 8478240d28..cea54a2984 100644
--- a/src/network/kernel/qhostaddress.h
+++ b/src/network/kernel/qhostaddress.h
@@ -124,6 +124,7 @@ public:
     bool isInSubnet(const QPair<QHostAddress, int> &subnet) const;
 
     bool isLoopback() const;
+    bool isMulticast() const;
 
     static QPair<QHostAddress, int> parseSubnet(const QString &subnet);