3 files changed, 14 insertions, 21 deletions
diff --git a/fluid/nodes/Function_Node.cxx b/fluid/nodes/Function_Node.cxx
index 095b3fc5f..3e98a898f 100644
--- a/fluid/nodes/Function_Node.cxx
+++ b/fluid/nodes/Function_Node.cxx
@@ -1514,8 +1514,7 @@ Class_Node Class_Node::prototype;
 Class_Node::Class_Node() :
   Node(),
   subclass_of(nullptr),
-  public_(1),
-  class_prefix(nullptr)
+  public_(1)
 { }
 
 /**
@@ -1524,8 +1523,6 @@ Class_Node::Class_Node() :
 Class_Node::~Class_Node() {
   if (subclass_of)
     free((void*)subclass_of);
-  if (class_prefix)
-    free((void*)class_prefix);
 }
 
 /**
@@ -1536,14 +1533,6 @@ int Class_Node::is_public() const {
 }
 
 /**
- Set the prefixx string.
- */
-void Class_Node::prefix(const char*p) {
-  free((void*) class_prefix);
-  class_prefix=fl_strdup(p ? p : "" );
-}
-
-/**
  Make a new class node.
  \param[in] strategy add after current or as last child
  \return new Class node
@@ -1559,7 +1548,7 @@ Node *Class_Node::make(Strategy strategy) {
   }
   Class_Node *o = new Class_Node();
   o->name("UserInterface");
-  o->class_prefix = nullptr;
+  o->prefix("");
   o->subclass_of = nullptr;
   o->public_ = 1;
   o->add(anchor, strategy);
@@ -1615,8 +1604,8 @@ void Class_Node::write_code1(fld::io::Code_Writer& f) {
   write_public_state = 0;
   f.write_h("\n");
   write_comment_h(f);
-  if (prefix() && strlen(prefix()))
-    f.write_h("class %s %s ", prefix(), name());
+  if (!prefix().empty())
+    f.write_h("class %s %s ", prefix().c_str(), name());
   else
     f.write_h("class %s ", name());
   if (subclass_of) f.write_h(": %s ", subclass_of);
diff --git a/fluid/nodes/Function_Node.h b/fluid/nodes/Function_Node.h
index 56a0046e0..282f33312 100644
--- a/fluid/nodes/Function_Node.h
+++ b/fluid/nodes/Function_Node.h
@@ -34,6 +34,8 @@
 #include <stdarg.h>
 #include <stdlib.h>
 
+#include <string>
+
 extern class Class_Node *current_class;
 
 int has_toplevel_function(const char *rtype, const char *sig);
@@ -271,7 +273,7 @@ public:
 private:
   const char* subclass_of;
   char public_;
-  const char* class_prefix;
+  std::string prefix_;
 public:
   Class_Node();
   ~Class_Node();
@@ -298,8 +300,10 @@ public:
   void visibility(char v) { public_ = v; }
 
   // class prefix attribute access
-  void prefix(const char* p);
-  const char*  prefix() const {return class_prefix;}
+  /** Set the text between `class` and the class name */
+  void prefix(const std::string& p) { prefix_ = p; }
+  /** Get the text between `class` and the class name */
+  std::string prefix() const { return prefix_; }
 };
 
 #endif // FLUID_NODES_FUNCTION_NODE_H
diff --git a/fluid/nodes/Node.cxx b/fluid/nodes/Node.cxx
index 0b1cb2d4d..7557e61f4 100644
--- a/fluid/nodes/Node.cxx
+++ b/fluid/nodes/Node.cxx
@@ -889,9 +889,9 @@ void Node::write(fld::io::Project_Writer &f) {
   f.write_word(type_name());
 
   if (is_class()) {
-    const char * p =  ((Class_Node*)this)->prefix();
-    if (p &&  strlen(p))
-      f.write_word(p);
+    auto p = ((Class_Node*)this)->prefix();
+    if (!p.empty())
+      f.write_word(p.c_str());
   }
 
   f.write_word(name());