fixed possible SEGFAULT in ceateRequest; new stream operator for Field and PVField

src/copy/createRequest.cpp

@@ -454,12 +454,14 @@ public:
                 }
             }
             StructureConstPtr structure = fieldCreate->createStructure(names, fields);
+            if(!structure) throw std::invalid_argument("bad request " + crequest);
             PVStructurePtr pvStructure = pvDataCreate->createPVStructure(structure);
             for(size_t i=0; i<optionList.size(); ++i) {
                 OptionPair pair = optionList[i];
                 string name = pair.name;
                 string value = pair.value;
                 PVStringPtr pvField = pvStructure->getSubField<PVString>(name);
+                if(!pvField) throw std::invalid_argument("bad request " + crequest);
                 pvField->put(value);
             }
             optionList.clear();

src/factory/FieldCreateFactory.cpp

@@ -1230,3 +1230,12 @@ FieldCreatePtr getFieldCreate() {
 }
 
 }}
+
+namespace std{
+    std::ostream& operator<<(std::ostream& o, const epics::pvData::Field *ptr)
+    {
+        if(ptr) return o << *ptr;
+        return o << "nullptr";
+    }
+}
+

src/factory/PVDataCreateFactory.cpp

@@ -741,3 +741,12 @@ PVDataCreatePtr getPVDataCreate() {
 }
 
 }}
+
+namespace std{
+    std::ostream& operator<<(std::ostream& o, const epics::pvData::PVField *ptr)
+    {
+        if(ptr) return o << *ptr;
+        return o << "nullptr";
+    }
+}
+

src/pv/pvData.h

@@ -1565,6 +1565,14 @@ private:
 epicsShareExtern PVDataCreatePtr getPVDataCreate();
 
 }}
+
+/**
+ * stream support for pvField
+ */
+namespace std{
+    std::ostream& operator<<(std::ostream& o, const epics::pvData::PVField *ptr);
+}
+
 #endif  /* PVDATA_H */
 
 /** @page Overview Documentation

src/pv/pvIntrospect.h

@@ -1220,4 +1220,12 @@ struct StructureArrayHashFunction {
 };
 
 }}
+
+/**
+ * stream support for Field
+ */
+namespace std{
+    std::ostream& operator<<(std::ostream& o, const epics::pvData::Field *ptr);
+}
+
 #endif  /* PVINTROSPECT_H */