Remove default argument from declarations of qHash as friend

It's illegal in C++11: §8.3.6.4 [dcl.fct.default]
"If a friend declaration specifies a default argument expression,
that declaration shall be a definition and shall be the only declaration
of the function or function template in the translation unit."

Clang is starting to enforce this, thus it's making qtbase not compiling.

Task-number: QTBUG-32100
Change-Id: Ifd9d4f62354d7cf4ccf275f36aab64e05c59efff
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

3 files changed, 14 insertions, 3 deletions

diff --git a/src/corelib/io/qurl.h b/src/corelib/io/qurl.h
index de4ce754fb..cf208bf71e 100644
--- a/src/corelib/io/qurl.h
+++ b/src/corelib/io/qurl.h
@@ -114,6 +114,10 @@ public:
 template<typename E1, typename E2>
 class QTypeInfo<QUrlTwoFlags<E1, E2> > : public QTypeInfoMerger<QUrlTwoFlags<E1, E2>, E1, E2> {};
 
+class QUrl;
+// qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
+Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed = 0) Q_DECL_NOTHROW;
+
 class Q_CORE_EXPORT QUrl
 {
 public:
@@ -324,7 +328,7 @@ public:
     static QList<QUrl> fromStringList(const QStringList &uris, ParsingMode mode = TolerantMode);
 
     static void setIdnWhitelist(const QStringList &);
-    friend Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed = 0) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed) Q_DECL_NOTHROW;
 
 private:
     QUrlPrivate *d;
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index 215ccce44d..f3bf2c1019 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -98,6 +98,9 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QModelIndex &);
 
 class QPersistentModelIndexData;
 
+// qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
+uint qHash(const QPersistentModelIndex &index, uint seed = 0);
+
 class Q_CORE_EXPORT QPersistentModelIndex
 {
 public:
@@ -128,7 +131,7 @@ public:
     bool isValid() const;
 private:
     QPersistentModelIndexData *d;
-    friend uint qHash(const QPersistentModelIndex &, uint seed = 0);
+    friend uint qHash(const QPersistentModelIndex &, uint seed);
 #ifndef QT_NO_DEBUG_STREAM
     friend Q_CORE_EXPORT QDebug operator<<(QDebug, const QPersistentModelIndex &);
 #endif
diff --git a/src/network/kernel/qhostaddress.h b/src/network/kernel/qhostaddress.h
index 77a2ec4105..49032850be 100644
--- a/src/network/kernel/qhostaddress.h
+++ b/src/network/kernel/qhostaddress.h
@@ -64,6 +64,10 @@ public:
 
 typedef QIPv6Address Q_IPV6ADDR;
 
+class QHostAddress;
+// qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
+Q_NETWORK_EXPORT uint qHash(const QHostAddress &key, uint seed = 0);
+
 class Q_NETWORK_EXPORT QHostAddress
 {
 public:
@@ -121,7 +125,7 @@ public:
 
     static QPair<QHostAddress, int> parseSubnet(const QString &subnet);
 
-    friend Q_NETWORK_EXPORT uint qHash(const QHostAddress &key, uint seed = 0);
+    friend Q_NETWORK_EXPORT uint qHash(const QHostAddress &key, uint seed);
 protected:
     QScopedPointer<QHostAddressPrivate> d;
 };