Add explicit and make public headers compile with -Wzero-as-null-pointer-constant (take 2)

... or equivalent.

QtBase 5.6 headers already compile that way, so let the other
modules follow suit.

Added explicit where it was missing. This is not a source-
incompatible change, because code that breaks by this is
a bug.

Change-Id: Iae024c4aa307bc891e244f7a8041846cef747ca4
Task-number: QTBUG-45291
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

4 files changed, 5 insertions, 5 deletions

diff --git a/src/scxml/qscxmlcppdatamodel.h b/src/scxml/qscxmlcppdatamodel.h
index f6e344d..48c5178 100644
--- a/src/scxml/qscxmlcppdatamodel.h
+++ b/src/scxml/qscxmlcppdatamodel.h
@@ -58,7 +58,7 @@ class Q_SCXML_EXPORT QScxmlCppDataModel: public QScxmlDataModel
     Q_OBJECT
     Q_DECLARE_PRIVATE(QScxmlCppDataModel)
 public:
-    QScxmlCppDataModel(QObject *parent = 0);
+    explicit QScxmlCppDataModel(QObject *parent = nullptr);
 
     bool setup(const QVariantMap &initialDataValues) Q_DECL_OVERRIDE;
 
diff --git a/src/scxml/qscxmldatamodel.h b/src/scxml/qscxmldatamodel.h
index 75c55e6..63143d1 100644
--- a/src/scxml/qscxmldatamodel.h
+++ b/src/scxml/qscxmldatamodel.h
@@ -68,7 +68,7 @@ public:
     };
 
 public:
-    QScxmlDataModel(QObject *parent = 0);
+    explicit QScxmlDataModel(QObject *parent = nullptr);
 
     void setStateMachine(QScxmlStateMachine *stateMachine);
     QScxmlStateMachine *stateMachine() const;
@@ -95,7 +95,7 @@ Q_SIGNALS:
     void stateMachineChanged(QScxmlStateMachine *stateMachine);
 
 protected:
-    QScxmlDataModel(QScxmlDataModelPrivate &dd, QObject *parent = 0);
+    explicit QScxmlDataModel(QScxmlDataModelPrivate &dd, QObject *parent = nullptr);
 #ifndef Q_QDOC
     QScxmlTableData *tableData() const;
 #endif // Q_QDOC
diff --git a/src/scxml/qscxmlecmascriptdatamodel.h b/src/scxml/qscxmlecmascriptdatamodel.h
index 0b0708c..0db8533 100644
--- a/src/scxml/qscxmlecmascriptdatamodel.h
+++ b/src/scxml/qscxmlecmascriptdatamodel.h
@@ -51,7 +51,7 @@ class Q_SCXML_EXPORT QScxmlEcmaScriptDataModel: public QScxmlDataModel
     Q_OBJECT
     Q_DECLARE_PRIVATE(QScxmlEcmaScriptDataModel)
 public:
-    QScxmlEcmaScriptDataModel(QObject *parent = 0);
+    explicit QScxmlEcmaScriptDataModel(QObject *parent = nullptr);
 
     bool setup(const QVariantMap &initialDataValues) Q_DECL_OVERRIDE;
 
diff --git a/src/scxml/qscxmlnulldatamodel.h b/src/scxml/qscxmlnulldatamodel.h
index 5fb28d9..cb47e4e 100644
--- a/src/scxml/qscxmlnulldatamodel.h
+++ b/src/scxml/qscxmlnulldatamodel.h
@@ -50,7 +50,7 @@ class Q_SCXML_EXPORT QScxmlNullDataModel: public QScxmlDataModel
     Q_OBJECT
     Q_DECLARE_PRIVATE(QScxmlNullDataModel)
 public:
-    QScxmlNullDataModel(QObject *parent = 0);
+    explicit QScxmlNullDataModel(QObject *parent = nullptr);
 
     bool setup(const QVariantMap &initialDataValues) Q_DECL_OVERRIDE;