Implement generation of clone functions

New test: clone.

36 files changed, 2734 insertions, 117 deletions

diff --git a/NEWS b/NEWS
index 1c4718b..08c82ca 100644
--- a/NEWS
+++ b/NEWS
@@ -44,6 +44,10 @@ Version 3.2.0
     Section 4.3, "Enumerations" in the Getting Started Guide for more
     information.
 
+  * New option, --generate-clone, triggers the generation of clone functions
+    for variable-length types. These functions allow you to make dynamically-
+    allocated copies of variable-length objects.
+
   * New configuration parameter, XSDE_STL_ITERATOR, makes iterators
     provided by the mapping conform to the STL requirements. This feature
     requires working <iterator> header and allows you to use the standard
diff --git a/dist/tests/cxx/hybrid/makefile b/dist/tests/cxx/hybrid/makefile
index ddcf464..7e78d9f 100644
--- a/dist/tests/cxx/hybrid/makefile
+++ b/dist/tests/cxx/hybrid/makefile
@@ -30,7 +30,7 @@ dirs += binary/xdr
 endif
 
 ifeq ($(XSDE_PARSER_VALIDATION),y)
-dirs += choice recursive
+dirs += choice recursive clone
 endif
 
 endif # XSDE_IOSTREAM
diff --git a/dist/tests/cxx/hybrid/nmakefile b/dist/tests/cxx/hybrid/nmakefile
index 1127649..b31619b 100644
--- a/dist/tests/cxx/hybrid/nmakefile
+++ b/dist/tests/cxx/hybrid/nmakefile
@@ -30,7 +30,7 @@ dirs = $(dirs) binary/xdr
 !endif
 
 !if "$(XSDE_PARSER_VALIDATION)" == "y"
-dirs = $(dirs) choice recursive
+dirs = $(dirs) choice recursive clone
 !endif
 
 !endif # XSDE_IOSTREAM
diff --git a/documentation/cxx/hybrid/guide/index.xhtml b/documentation/cxx/hybrid/guide/index.xhtml
index 39d7e9b..7d33a4e 100644
--- a/documentation/cxx/hybrid/guide/index.xhtml
+++ b/documentation/cxx/hybrid/guide/index.xhtml
@@ -2024,10 +2024,21 @@ private:
      (see <a href="#3.8">Section 3.8, "Custom Allocators"</a>),
      the object model expects you to allocate such an object with
      operator <code>new</code> and will eventually delete it
-     with operator <code>delete</code>. You can also request generation
-     of detach functions with the <code>--generate-detach</code> compiler
-     option. These functions allow you to detach a variable-length
-     object from the object model. As an example, let us extend
+     with operator <code>delete</code>.</p>
+
+  <p>If you wish to make copies of variable-length objects, then
+     you can request the generation of the object cloning functions
+     with the <code>--generate-clone</code> compiler
+     option. When this option is specified, each variable-length
+     type implements the <code>_clone()</code> function which returns
+     a dynamically-allocated copy of the object or <code>NULL</code>
+     if the allocation failed and C++ exceptions are disabled (see
+     <a href="#3.3">Section 3.3, "C++ Exceptions"</a>). </p>
+
+  <p>You can also request generation of detach functions with the
+     <code>--generate-detach</code> compiler option. These functions
+     allow you to detach a variable-length object from the object model.
+     As an example, let us extend
      our <code>people.xsd</code> schema with the following type:</p>
 
   <pre class="xml">
@@ -2039,8 +2050,9 @@ private:
 &lt;/xs:complexType>
   </pre>
 
-  <p>If we compile it with XSD/e and specify the <code>--generate-detach</code>
-     option, we will get the following C++ class:</p>
+  <p>If we compile it with XSD/e and specify the
+     <code>--generate-clone</code> and <code>--generate-detach</code>
+     options, we will get the following C++ class:</p>
 
   <pre class="c++">
 // staff (variable-length)
@@ -2050,6 +2062,9 @@ class staff
 public:
   staff ();
 
+  staff*
+  _clone () const;
+
 private:
   staff (const staff&amp;);
   staff&amp; operator= (const staff&amp;);
@@ -4143,7 +4158,9 @@ for (people::person_iterator i = ps.begin (); i != ps.end (); ++i)
      type is always variable-length which means objects of polymorphic
      types are allocated dynamically and are stored and passed around
      as pointers or references. A polymorphic type also defines a
-     virtual destructor which allows you to delete an instance of a
+     virtual <code>_clone()</code> function (see <a href="#4.2">Section 4.2,
+     "Memory Management"</a>) and a virtual destructor
+     which allow you to copy and delete an instance of a
      polymorphic type via a pointer to its base. The following code
      fragment shows how we can parse, access, modify, and serialize
      the above XML document:</p>
@@ -4957,11 +4974,15 @@ namespace xml_schema
 
   public:
     void
+    assign (void* data, size_t size);
+
+    void
     attach (void* data, size_t size, size_t capacity);
 
     void*
     detach ();
 
+
     void
     swap (buffer&amp;);
 
@@ -5048,6 +5069,9 @@ namespace xml_schema
 
   public:
     error
+    assign (void* data, size_t size);
+
+    error
     attach (void* data, size_t size, size_t capacity);
 
     void*
diff --git a/documentation/xsde.1 b/documentation/xsde.1
index a4b55dc..4257882 100644
--- a/documentation/xsde.1
+++ b/documentation/xsde.1
@@ -1006,6 +1006,10 @@ documents.
 .IP "\fB\--suppress-enum\fR"
 Suppress the generation of the XML Schema enumeration to C++ enum mapping.
 
+.IP "\fB\--generate-clone\fR"
+Generate clone functions for variable-length types. These functions allow
+you to make dynamically-allocated copies of variable-length objects.
+
 .IP "\fB\--generate-detach\fR"
 Generate detach functions for elements and attributes of variable-length
 types. These functions, for example, allow you to move sub-trees in the
diff --git a/documentation/xsde.xhtml b/documentation/xsde.xhtml
index 859719e..9797ba9 100644
--- a/documentation/xsde.xhtml
+++ b/documentation/xsde.xhtml
@@ -870,6 +870,11 @@
     <dd>Suppress the generation of the XML Schema enumeration to C++
         enum mapping.</dd>
 
+    <dt><code><b>--generate-clone</b></code></dt>
+    <dd>Generate clone functions for variable-length types. These
+        functions allow you to make dynamically-allocated copies of
+        variable-length objects.</dd>
+
     <dt><code><b>--generate-detach</b></code></dt>
     <dd>Generate detach functions for elements and attributes of
         variable-length types. These functions, for example, allow
diff --git a/libxsde/xsde/cxx/buffer.cxx b/libxsde/xsde/cxx/buffer.cxx
index d9102ae..4084cde 100644
--- a/libxsde/xsde/cxx/buffer.cxx
+++ b/libxsde/xsde/cxx/buffer.cxx
@@ -110,6 +110,58 @@ namespace xsde
         return true;
       }
     }
+
+    void buffer::
+    assign (void* data, size_t size)
+    {
+      capacity (size);
+      size_ = size;
+
+      if (size_)
+        memcpy (data_, data, size_);
+    }
+
+    struct buffer_guard
+    {
+      buffer_guard (buffer* p) : p_ (p) {}
+
+      ~buffer_guard ()
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete p_;
+#else
+        if (p_ != 0)
+        {
+          p_->~buffer ();
+          cxx::free (p_);
+        }
+#endif
+      }
+
+      void
+      release () { p_ = 0; }
+
+    private:
+      buffer* p_;
+    };
+
+    buffer* buffer::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      buffer* c = new buffer;
+#else
+      // Default buffer c-tor cannot throw so we don't need alloc_guard.
+      //
+      buffer* c = static_cast<buffer*> (cxx::alloc (sizeof (buffer)));
+      new (c) buffer;
+#endif
+      buffer_guard g (c);
+      _copy (*c);
+      g.release ();
+      return c;
+    }
+
 #else
     buffer::error buffer::
     capacity (size_t capacity, bool copy, bool* moved)
@@ -156,6 +208,50 @@ namespace xsde
 
       return error_none;
     }
+
+    buffer::error buffer::
+    assign (void* data, size_t size)
+    {
+      if (error r = capacity (size))
+        return r;
+
+      size_ = size;
+
+      if (size_)
+        memcpy (data_, data, size_);
+
+      return error_none;
+    }
+
+    buffer* buffer::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      buffer* c = new buffer;
+#else
+      buffer* c = static_cast<buffer*> (cxx::alloc (sizeof (buffer)));
+#endif
+
+      if (c == 0)
+        return 0;
+
+#ifdef XSDE_CUSTOM_ALLOCATOR
+      new (c) buffer;
+#endif
+
+      if (!_copy (*c))
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete c;
+#else
+        c->~buffer ();
+        cxx::free (c);
+#endif
+        return 0;
+      }
+
+      return c;
+    }
 #endif
   }
 }
diff --git a/libxsde/xsde/cxx/buffer.hxx b/libxsde/xsde/cxx/buffer.hxx
index 7ea1adf..2957a0a 100644
--- a/libxsde/xsde/cxx/buffer.hxx
+++ b/libxsde/xsde/cxx/buffer.hxx
@@ -60,6 +60,13 @@ namespace xsde
 #else
       void
 #endif
+      assign (void* data, size_t size);
+
+#ifndef XSDE_EXCEPTIONS
+      error
+#else
+      void
+#endif
       attach (void* data, size_t size, size_t capacity);
 
       void*
@@ -68,6 +75,16 @@ namespace xsde
       void
       swap (buffer&);
 
+      buffer*
+      _clone () const;
+
+#ifndef XSDE_EXCEPTIONS
+      bool
+#else
+      void
+#endif
+      _copy (buffer&) const;
+
     public:
       size_t
       capacity () const;
diff --git a/libxsde/xsde/cxx/buffer.ixx b/libxsde/xsde/cxx/buffer.ixx
index 2229396..d9c71eb 100644
--- a/libxsde/xsde/cxx/buffer.ixx
+++ b/libxsde/xsde/cxx/buffer.ixx
@@ -220,5 +220,21 @@ namespace xsde
     {
       return !(x == y);
     }
+
+    //
+    //
+#ifndef XSDE_EXCEPTIONS
+    inline bool buffer::
+    _copy (buffer& c) const
+    {
+      return c.assign (data_, size_) == error_none;
+    }
+#else
+    inline void buffer::
+    _copy (buffer& c) const
+    {
+      c.assign (data_, size_);
+    }
+#endif
   }
 }
diff --git a/libxsde/xsde/cxx/guard.hxx b/libxsde/xsde/cxx/guard.hxx
new file mode 100644
index 0000000..3190983
--- /dev/null
+++ b/libxsde/xsde/cxx/guard.hxx
@@ -0,0 +1,48 @@
+// file      : xsde/cxx/guard.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2005-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+#ifndef XSDE_CXX_GUARD_HXX
+#define XSDE_CXX_GUARD_HXX
+
+#include <xsde/cxx/config.hxx>
+
+#ifdef XSDE_CUSTOM_ALLOCATOR
+#  include <xsde/cxx/allocator.hxx>
+#endif
+
+namespace xsde
+{
+  namespace cxx
+  {
+#ifdef XSDE_EXCEPTIONS
+    template <typename T>
+    struct guard
+    {
+      guard (T* p) : p_ (p) {}
+
+      ~guard ()
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete p_;
+#else
+        if (p_ != 0)
+        {
+          p_->~T ();
+          cxx::free (p_);
+        }
+#endif
+      }
+
+      void
+      release () { p_ = 0; }
+
+    private:
+      T* p_;
+    };
+#endif // XSDE_EXCEPTIONS
+  }
+}
+
+#endif // XSDE_CXX_GUARD_HXX
diff --git a/libxsde/xsde/cxx/hybrid/base.hxx b/libxsde/xsde/cxx/hybrid/base.hxx
index 89431a2..a7b1e2a 100644
--- a/libxsde/xsde/cxx/hybrid/base.hxx
+++ b/libxsde/xsde/cxx/hybrid/base.hxx
@@ -10,6 +10,7 @@
 
 #ifndef XSDE_STL
 #  include <string.h> // strcmp
+#  include <xsde/cxx/strdupx.hxx>
 #endif
 
 #ifdef XSDE_CUSTOM_ALLOCATOR
@@ -599,6 +600,26 @@ namespace xsde
 
         string_base& operator= (char* x) {base_value (x); return *this;}
 
+#ifndef XSDE_EXCEPTIONS
+        bool
+#else
+        void
+#endif
+        _copy (string_base& c) const
+        {
+          char* x = strdupx (x_);
+
+#ifndef XSDE_EXCEPTIONS
+          if (x == 0)
+            return false;
+#endif
+          c.base_value (x);
+
+#ifndef XSDE_EXCEPTIONS
+          return true;
+#endif
+        }
+
       protected:
         char* x_;
       };
diff --git a/libxsde/xsde/cxx/hybrid/sequence.cxx b/libxsde/xsde/cxx/hybrid/sequence.cxx
index bf5f3c7..5293616 100644
--- a/libxsde/xsde/cxx/hybrid/sequence.cxx
+++ b/libxsde/xsde/cxx/hybrid/sequence.cxx
@@ -26,6 +26,51 @@ namespace xsde
 
         size_ = 0;
       }
+
+#ifdef XSDE_EXCEPTIONS
+      void data_sequence::
+      copy (data_sequence& c) const
+      {
+        if (c.size_ != 0)
+          c.clear ();
+
+        c.destructor_ = destructor_;
+        c.clone_ = clone_;
+
+        c.reserve (size_);
+
+        for (; c.size_ < size_; ++c.size_)
+        {
+          static_cast<void**> (c.data_)[c.size_] =
+            clone_ (static_cast<void**> (data_)[c.size_], c.size_);
+        }
+      }
+#else
+      sequence_base::error data_sequence::
+      copy (data_sequence& c) const
+      {
+        if (c.size_ != 0)
+          c.clear ();
+
+        c.destructor_ = destructor_;
+        c.clone_ = clone_;
+
+        if (error r = c.reserve (size_))
+          return r;
+
+        for (; c.size_ < size_; ++c.size_)
+        {
+          void* x = clone_ (static_cast<void**> (data_)[c.size_], c.size_);
+
+          if (x == 0)
+            return error_no_memory;
+
+          static_cast<void**> (c.data_)[c.size_] = x;
+        }
+
+        return error_none;
+      }
+#endif
     }
   }
 }
diff --git a/libxsde/xsde/cxx/hybrid/sequence.hxx b/libxsde/xsde/cxx/hybrid/sequence.hxx
index fa5c697..e21f219 100644
--- a/libxsde/xsde/cxx/hybrid/sequence.hxx
+++ b/libxsde/xsde/cxx/hybrid/sequence.hxx
@@ -128,6 +128,13 @@ namespace xsde
 
         void
         swap (pod_sequence&);
+
+#ifndef XSDE_EXCEPTIONS
+        error
+#else
+        void
+#endif
+        copy (pod_sequence&) const;
       };
 
       // Sequence with fixed-length elements.
@@ -230,6 +237,13 @@ namespace xsde
         void
         swap (fix_sequence&);
 
+#ifndef XSDE_EXCEPTIONS
+        error
+#else
+        void
+#endif
+        copy (fix_sequence&) const;
+
       private:
         static void
         move_ (void* dst, void* src, size_t n);
@@ -831,6 +845,13 @@ namespace xsde
         void
         swap (var_sequence&);
 
+#ifndef XSDE_EXCEPTIONS
+        error
+#else
+        void
+#endif
+        copy (var_sequence&) const;
+
 #ifdef XSDE_EXCEPTIONS
       public:
         struct guard
@@ -877,10 +898,14 @@ namespace xsde
         data_sequence ();
 
         typedef void (*destroy_func) (void* data, size_t pos);
+        typedef void* (*clone_func) (void* data, size_t pos);
 
         void
         destructor (destroy_func);
 
+        void
+        clone (clone_func);
+
       public:
         iterator
         begin ();
@@ -953,8 +978,16 @@ namespace xsde
         void
         swap (data_sequence&);
 
+#ifndef XSDE_EXCEPTIONS
+        error
+#else
+        void
+#endif
+        copy (data_sequence&) const;
+
       private:
         destroy_func destructor_;
+        clone_func clone_;
       };
     }
   }
diff --git a/libxsde/xsde/cxx/hybrid/sequence.ixx b/libxsde/xsde/cxx/hybrid/sequence.ixx
index 1ec2a4c..e53b774 100644
--- a/libxsde/xsde/cxx/hybrid/sequence.ixx
+++ b/libxsde/xsde/cxx/hybrid/sequence.ixx
@@ -167,6 +167,13 @@ namespace xsde
         memcpy (data_, p, n * sizeof (T));
         size_ = n;
       }
+
+      template <typename T>
+      inline void pod_sequence<T>::
+      copy (pod_sequence& c) const
+      {
+        c.assign (begin (), size ());
+      }
 #else
       template <typename T>
       inline sequence_base::error pod_sequence<T>::
@@ -238,6 +245,13 @@ namespace xsde
         size_ = n;
         return error_none;
       }
+
+      template <typename T>
+      inline sequence_base::error pod_sequence<T>::
+      copy (pod_sequence& c) const
+      {
+        return c.assign (begin (), size ());
+      }
 #endif
 
       //
@@ -387,6 +401,13 @@ namespace xsde
         if (capacity_ < n)
           grow_ (n, sizeof (T), &move_);
       }
+
+      template <typename T>
+      inline void fix_sequence<T>::
+      copy (fix_sequence& c) const
+      {
+        c.assign (begin (), size ());
+      }
 #else
       template <typename T>
       inline sequence_base::error fix_sequence<T>::
@@ -448,6 +469,13 @@ namespace xsde
           r = grow_ (n, sizeof (T), &move_);
         return r;
       }
+
+      template <typename T>
+      inline sequence_base::error fix_sequence<T>::
+      copy (fix_sequence& c) const
+      {
+        return c.assign (begin (), size ());
+      }
 #endif
 
       //
@@ -741,7 +769,7 @@ namespace xsde
 
       inline data_sequence::
       data_sequence ()
-          : destructor_ (0)
+          : destructor_ (0), clone_ (0)
       {
       }
 
@@ -751,6 +779,12 @@ namespace xsde
         destructor_ = d;
       }
 
+      inline void data_sequence::
+      clone (data_sequence::clone_func c)
+      {
+        clone_ = c;
+      }
+
       inline size_t data_sequence::
       max_size () const
       {
diff --git a/libxsde/xsde/cxx/hybrid/sequence.txx b/libxsde/xsde/cxx/hybrid/sequence.txx
index b79e9d5..5d7df7d 100644
--- a/libxsde/xsde/cxx/hybrid/sequence.txx
+++ b/libxsde/xsde/cxx/hybrid/sequence.txx
@@ -30,7 +30,9 @@ namespace xsde
       void fix_sequence<T>::
       assign (const T* p, size_t n)
       {
-        clear ();
+        if (size_ != 0)
+          clear ();
+
         reserve (n);
 
         for (; size_ < n; ++size_)
@@ -41,7 +43,8 @@ namespace xsde
       sequence_base::error fix_sequence<T>::
       assign (const T* p, size_t n)
       {
-        clear ();
+        if (size_ != 0)
+          clear ();
 
         if (error r = reserve (n))
           return r;
@@ -166,6 +169,47 @@ namespace xsde
 
         size_ = 0;
       }
+
+#ifdef XSDE_EXCEPTIONS
+      template <typename T>
+      void var_sequence<T>::
+      copy (var_sequence& c) const
+      {
+        if (c.size_ != 0)
+          c.clear ();
+
+        c.reserve (size_);
+
+        for (; c.size_ < size_; ++c.size_)
+        {
+          static_cast<T**> (c.data_)[c.size_] =
+            static_cast<T**> (data_)[c.size_]->_clone ();
+        }
+      }
+#else
+      template <typename T>
+      sequence_base::error var_sequence<T>::
+      copy (var_sequence& c) const
+      {
+        if (c.size_ != 0)
+          c.clear ();
+
+        if (error r = c.reserve (size_))
+          return r;
+
+        for (; c.size_ < size_; ++c.size_)
+        {
+          T* x = static_cast<T**> (data_)[c.size_]->_clone ();
+
+          if (x == 0)
+            return error_no_memory;
+
+          static_cast<T**> (c.data_)[c.size_] = x;
+        }
+
+        return error_none;
+      }
+#endif
     }
   }
 }
diff --git a/libxsde/xsde/cxx/qname.cxx b/libxsde/xsde/cxx/qname.cxx
index be196be..f1e4238 100644
--- a/libxsde/xsde/cxx/qname.cxx
+++ b/libxsde/xsde/cxx/qname.cxx
@@ -10,11 +10,83 @@ namespace xsde
 {
   namespace cxx
   {
-#ifndef XSDE_EXCEPTIONS
-    qname::error qname::
+
+#ifdef XSDE_EXCEPTIONS
+
+    void qname::
+    prefix_copy (const char* prefix)
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      delete[] prefix_;
 #else
+      cxx::free (prefix_);
+#endif
+
+      if (prefix)
+        prefix_ = strdupx (prefix);
+      else
+        prefix_ = 0;
+    }
+
     void qname::
+    name_copy (const char* name)
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      delete[] name_;
+#else
+      cxx::free (name_);
+#endif
+
+      if (name)
+        name_ = strdupx (name);
+      else
+        name_ = 0;
+    }
+
+    struct qname_guard
+    {
+      qname_guard (qname* p) : p_ (p) {}
+
+      ~qname_guard ()
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete p_;
+#else
+        if (p_ != 0)
+        {
+          p_->~qname ();
+          cxx::free (p_);
+        }
 #endif
+      }
+
+      void
+      release () { p_ = 0; }
+
+    private:
+      qname* p_;
+    };
+
+    qname* qname::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      qname* c = new qname;
+#else
+      // Default qname c-tor cannot throw so we don't need alloc_guard.
+      //
+      qname* c = static_cast<qname*> (cxx::alloc (sizeof (qname)));
+      new (c) qname;
+#endif
+      qname_guard g (c);
+      _copy (*c);
+      g.release ();
+      return c;
+    }
+
+#else
+
+    qname::error qname::
     prefix_copy (const char* prefix)
     {
 #ifndef XSDE_CUSTOM_ALLOCATOR
@@ -27,24 +99,16 @@ namespace xsde
       {
         prefix_ = strdupx (prefix);
 
-#ifndef XSDE_EXCEPTIONS
         if (prefix_ == 0)
           return error_no_memory;
-#endif
       }
       else
         prefix_ = 0;
 
-#ifndef XSDE_EXCEPTIONS
       return error_none;
-#endif
     }
 
-#ifndef XSDE_EXCEPTIONS
     qname::error qname::
-#else
-    void qname::
-#endif
     name_copy (const char* name)
     {
 #ifndef XSDE_CUSTOM_ALLOCATOR
@@ -57,17 +121,45 @@ namespace xsde
       {
         name_ = strdupx (name);
 
-#ifndef XSDE_EXCEPTIONS
         if (name_ == 0)
           return error_no_memory;
-#endif
       }
       else
         name_ = 0;
 
-#ifndef XSDE_EXCEPTIONS
       return error_none;
+    }
+
+    qname* qname::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      qname* c = new qname;
+#else
+      qname* c = static_cast<qname*> (cxx::alloc (sizeof (qname)));
+#endif
+
+      if (c == 0)
+        return 0;
+
+#ifdef XSDE_CUSTOM_ALLOCATOR
+      new (c) qname;
 #endif
+
+      if (!_copy (*c))
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete c;
+#else
+        c->~qname ();
+        cxx::free (c);
+#endif
+        return 0;
+      }
+
+      return c;
     }
+
+#endif
   }
 }
diff --git a/libxsde/xsde/cxx/qname.hxx b/libxsde/xsde/cxx/qname.hxx
index 0b2d5f5..85b53bd 100644
--- a/libxsde/xsde/cxx/qname.hxx
+++ b/libxsde/xsde/cxx/qname.hxx
@@ -81,6 +81,16 @@ namespace xsde
       char*
       name_detach ();
 
+      qname*
+      _clone () const;
+
+#ifndef XSDE_EXCEPTIONS
+      bool
+#else
+      void
+#endif
+      _copy (qname&) const;
+
     private:
       char* prefix_;
       char* name_;
diff --git a/libxsde/xsde/cxx/qname.ixx b/libxsde/xsde/cxx/qname.ixx
index f449ef3..7a374c6 100644
--- a/libxsde/xsde/cxx/qname.ixx
+++ b/libxsde/xsde/cxx/qname.ixx
@@ -124,6 +124,24 @@ namespace xsde
       return r;
     }
 
+#ifdef XSDE_EXCEPTIONS
+    inline void qname::
+    _copy (qname& c) const
+    {
+      c.prefix_copy (prefix_);
+      c.name_copy (name_);
+    }
+#else
+    inline bool qname::
+    _copy (qname& c) const
+    {
+      if (c.prefix_copy (prefix_) || c.name_copy (name_))
+        return false;
+
+      return true;
+    }
+#endif
+
     //
     //
     inline bool
diff --git a/libxsde/xsde/cxx/string-sequence-stl.cxx b/libxsde/xsde/cxx/string-sequence-stl.cxx
index 255b341..2fd8a02 100644
--- a/libxsde/xsde/cxx/string-sequence-stl.cxx
+++ b/libxsde/xsde/cxx/string-sequence-stl.cxx
@@ -5,6 +5,10 @@
 
 #include <xsde/cxx/string-sequence-stl.hxx>
 
+#ifdef XSDE_CUSTOM_ALLOCATOR
+#  include <xsde/cxx/allocator.hxx>
+#endif
+
 namespace xsde
 {
   namespace cxx
@@ -20,6 +24,115 @@ namespace xsde
     }
 
 #ifdef XSDE_EXCEPTIONS
+    void string_sequence::
+    copy (string_sequence& c) const
+    {
+      if (c.size_ != 0)
+        c.clear ();
+
+      c.reserve (size_);
+
+      for (; c.size_ < size_; ++c.size_)
+      {
+        new (static_cast<std::string*> (c.data_) + c.size_) std::string (
+          static_cast<std::string*> (data_)[c.size_]);
+      }
+    }
+
+    struct string_sequence_guard
+    {
+      string_sequence_guard (string_sequence* p) : p_ (p) {}
+
+      ~string_sequence_guard ()
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete p_;
+#else
+        if (p_ != 0)
+        {
+          p_->~string_sequence ();
+          cxx::free (p_);
+        }
+#endif
+      }
+
+      void
+      release () { p_ = 0; }
+
+    private:
+      string_sequence* p_;
+    };
+
+    string_sequence* string_sequence::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      string_sequence* c = new string_sequence;
+#else
+      // Default string_sequence c-tor cannot throw so we don't need
+      // alloc_guard.
+      //
+      string_sequence* c = static_cast<string_sequence*> (
+        cxx::alloc (sizeof (string_sequence)));
+      new (c) string_sequence;
+#endif
+      string_sequence_guard g (c);
+      _copy (*c);
+      g.release ();
+      return c;
+    }
+#else
+    sequence_base::error string_sequence::
+    copy (string_sequence& c) const
+    {
+      if (c.size_ != 0)
+        c.clear ();
+
+      if (error r = c.reserve (size_))
+        return r;
+
+      for (; c.size_ < size_; ++c.size_)
+      {
+        new (static_cast<std::string*> (c.data_) + c.size_) std::string (
+          static_cast<std::string*> (data_)[c.size_]);
+      }
+
+      return error_none;
+    }
+
+    string_sequence* string_sequence::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      string_sequence* c = new string_sequence;
+#else
+      string_sequence* c = static_cast<string_sequence*> (
+        cxx::alloc (sizeof (string_sequence)));
+#endif
+
+      if (c == 0)
+        return 0;
+
+#ifdef XSDE_CUSTOM_ALLOCATOR
+      new (c) string_sequence;
+#endif
+
+      if (!_copy (*c))
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete c;
+#else
+        c->~string_sequence ();
+        cxx::free (c);
+#endif
+        return 0;
+      }
+
+      return c;
+    }
+#endif
+
+#ifdef XSDE_EXCEPTIONS
     struct guard
     {
       guard (std::string* p, size_t& n) : p_ (p), n_ (n) {}
diff --git a/libxsde/xsde/cxx/string-sequence-stl.hxx b/libxsde/xsde/cxx/string-sequence-stl.hxx
index 305fd0d..5e75ad8 100644
--- a/libxsde/xsde/cxx/string-sequence-stl.hxx
+++ b/libxsde/xsde/cxx/string-sequence-stl.hxx
@@ -106,6 +106,23 @@ namespace xsde
       void
       swap (string_sequence&);
 
+#ifndef XSDE_EXCEPTIONS
+      error
+#else
+      void
+#endif
+      copy (string_sequence&) const;
+
+      string_sequence*
+      _clone () const;
+
+#ifndef XSDE_EXCEPTIONS
+      bool
+#else
+      void
+#endif
+      _copy (string_sequence&) const;
+
     private:
       static void
       move_ (void* dst, void* src, size_t n);
diff --git a/libxsde/xsde/cxx/string-sequence-stl.ixx b/libxsde/xsde/cxx/string-sequence-stl.ixx
index 55e3d5d..ae09d04 100644
--- a/libxsde/xsde/cxx/string-sequence-stl.ixx
+++ b/libxsde/xsde/cxx/string-sequence-stl.ixx
@@ -134,8 +134,15 @@ namespace xsde
     reserve (size_t n)
     {
       if (capacity_ < n)
-        grow_ (n, sizeof (std::string*), &move_);
+        grow_ (n, sizeof (std::string), &move_);
     }
+
+    inline void string_sequence::
+    _copy (string_sequence& c) const
+    {
+      copy (c);
+    }
+
 #else
     inline sequence_base::error string_sequence::
     push_back (const std::string& x)
@@ -193,6 +200,12 @@ namespace xsde
         r = grow_ (n, sizeof (std::string), &move_);
       return r;
     }
+
+    inline bool string_sequence::
+    _copy (string_sequence& c) const
+    {
+      return copy (c) == error_none;
+    }
 #endif
 
     inline bool
diff --git a/libxsde/xsde/cxx/string-sequence.cxx b/libxsde/xsde/cxx/string-sequence.cxx
index 5387e79..63944fb 100644
--- a/libxsde/xsde/cxx/string-sequence.cxx
+++ b/libxsde/xsde/cxx/string-sequence.cxx
@@ -34,6 +34,64 @@ namespace xsde
 
       static_cast<char**> (data_)[size_++] = strdupx (cs);
     }
+
+    void string_sequence::
+    copy (string_sequence& c) const
+    {
+      if (c.size_ != 0)
+        c.clear ();
+
+      c.reserve (size_);
+
+      for (; c.size_ < size_; ++c.size_)
+      {
+        static_cast<char**> (c.data_)[c.size_] =
+          strdupx (static_cast<char**> (data_)[c.size_]);
+      }
+    }
+
+    struct string_sequence_guard
+    {
+      string_sequence_guard (string_sequence* p) : p_ (p) {}
+
+      ~string_sequence_guard ()
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete p_;
+#else
+        if (p_ != 0)
+        {
+          p_->~string_sequence ();
+          cxx::free (p_);
+        }
+#endif
+      }
+
+      void
+      release () { p_ = 0; }
+
+    private:
+      string_sequence* p_;
+    };
+
+    string_sequence* string_sequence::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      string_sequence* c = new string_sequence;
+#else
+      // Default string_sequence c-tor cannot throw so we don't need
+      // alloc_guard.
+      //
+      string_sequence* c = static_cast<string_sequence*> (
+        cxx::alloc (sizeof (string_sequence)));
+      new (c) string_sequence;
+#endif
+      string_sequence_guard g (c);
+      _copy (*c);
+      g.release ();
+      return c;
+    }
 #else
     string_sequence::error string_sequence::
     push_back_copy (const char* cs)
@@ -55,6 +113,59 @@ namespace xsde
 
       return r;
     }
+
+    sequence_base::error string_sequence::
+    copy (string_sequence& c) const
+    {
+      if (c.size_ != 0)
+        c.clear ();
+
+      if (error r = c.reserve (size_))
+        return r;
+
+      for (; c.size_ < size_; ++c.size_)
+      {
+        char* x = strdupx (static_cast<char**> (data_)[c.size_]);
+
+        if (x == 0)
+          return error_no_memory;
+
+        static_cast<char**> (c.data_)[c.size_] = x;
+      }
+
+      return error_none;
+    }
+
+    string_sequence* string_sequence::
+    _clone () const
+    {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+      string_sequence* c = new string_sequence;
+#else
+      string_sequence* c = static_cast<string_sequence*> (
+        cxx::alloc (sizeof (string_sequence)));
+#endif
+
+      if (c == 0)
+        return 0;
+
+#ifdef XSDE_CUSTOM_ALLOCATOR
+      new (c) string_sequence;
+#endif
+
+      if (!_copy (*c))
+      {
+#ifndef XSDE_CUSTOM_ALLOCATOR
+        delete c;
+#else
+        c->~string_sequence ();
+        cxx::free (c);
+#endif
+        return 0;
+      }
+
+      return c;
+    }
 #endif
 
     bool
diff --git a/libxsde/xsde/cxx/string-sequence.hxx b/libxsde/xsde/cxx/string-sequence.hxx
index c9a33e4..a94418a 100644
--- a/libxsde/xsde/cxx/string-sequence.hxx
+++ b/libxsde/xsde/cxx/string-sequence.hxx
@@ -123,6 +123,23 @@ namespace xsde
 
       void
       swap (string_sequence&);
+
+#ifndef XSDE_EXCEPTIONS
+      error
+#else
+      void
+#endif
+      copy (string_sequence&) const;
+
+      string_sequence*
+      _clone () const;
+
+#ifndef XSDE_EXCEPTIONS
+      bool
+#else
+      void
+#endif
+      _copy (string_sequence&) const;
     };
 
     bool
diff --git a/libxsde/xsde/cxx/string-sequence.ixx b/libxsde/xsde/cxx/string-sequence.ixx
index b902bd7..b74adf2 100644
--- a/libxsde/xsde/cxx/string-sequence.ixx
+++ b/libxsde/xsde/cxx/string-sequence.ixx
@@ -172,6 +172,12 @@ namespace xsde
       if (capacity_ < n)
         grow_ (n, sizeof (char*), 0);
     }
+
+    inline void string_sequence::
+    _copy (string_sequence& c) const
+    {
+      copy (c);
+    }
 #else
     inline sequence_base::error string_sequence::
     push_back (char* x)
@@ -244,6 +250,12 @@ namespace xsde
         r = grow_ (n, sizeof (char*), 0);
       return r;
     }
+
+    inline bool string_sequence::
+    _copy (string_sequence& c) const
+    {
+      return copy (c) == error_none;
+    }
 #endif
 
     inline char* string_sequence::
diff --git a/tests/cxx/hybrid/clone/driver.cxx b/tests/cxx/hybrid/clone/driver.cxx
new file mode 100644
index 0000000..5d044ca
--- /dev/null
+++ b/tests/cxx/hybrid/clone/driver.cxx
@@ -0,0 +1,79 @@
+// file      : tests/cxx/hybrid/clone/driver.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2006-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+// Test _clone() functionality.
+//
+
+#include <assert.h>
+#include <iostream>
+
+#include "test.hxx"
+#include "test-pimpl.hxx"
+#include "test-simpl.hxx"
+
+using namespace std;
+using namespace test;
+
+void
+data_destructor (void* p, size_t)
+{
+  delete static_cast<int*> (p);
+}
+
+void*
+data_clone (void* p, size_t)
+{
+  return new int (*static_cast<int*> (p));
+}
+
+int
+main (int argc, char* argv[])
+{
+  if (argc != 2)
+  {
+    cerr << "usage: " << argv[0] << " test.xml" << endl;
+    return 1;
+  }
+
+  // Parse.
+  //
+  root_paggr root_p;
+
+  xml_schema::document_pimpl doc_p (
+    root_p.root_parser (),
+    root_p.root_namespace (),
+    root_p.root_name ());
+
+  root_p.pre ();
+  doc_p.parse (argv[1]);
+  type* r = root_p.post ();
+
+  r->complex ().custom_data ().destructor (&data_destructor);
+  r->complex ().custom_data ().clone (&data_clone);
+  r->complex ().custom_data ().push_back (new int (123));
+
+  type* c = r->_clone ();
+  delete r;
+
+  assert (c->complex ().custom_data ().size () == 1);
+  assert (*static_cast<int*> (c->complex ().custom_data ()[0]) == 123);
+
+  // Serialize.
+  //
+  root_saggr root_s;
+
+  xml_schema::document_simpl doc_s (
+    root_s.root_serializer (),
+    root_s.root_namespace (),
+    root_s.root_name ());
+
+  doc_s.add_prefix ("t", "test");
+
+  root_s.pre (*c);
+  doc_s.serialize (cout, xml_schema::document_simpl::pretty_print);
+  root_s.post ();
+
+  delete c;
+}
diff --git a/tests/cxx/hybrid/clone/makefile b/tests/cxx/hybrid/clone/makefile
new file mode 100644
index 0000000..7138869
--- /dev/null
+++ b/tests/cxx/hybrid/clone/makefile
@@ -0,0 +1,109 @@
+# file      : tests/cxx/hybrid/clone/makefile
+# author    : Boris Kolpackov <boris@codesynthesis.com>
+# copyright : Copyright (c) 2006-2010 Code Synthesis Tools CC
+# license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+include $(dir $(lastword $(MAKEFILE_LIST)))../../../../build/bootstrap.make
+
+xsd := test.xsd
+cxx := driver.cxx
+
+obj := $(addprefix $(out_base)/,\
+$(cxx:.cxx=.o)       \
+$(xsd:.xsd=.o)       \
+$(xsd:.xsd=-pskel.o) \
+$(xsd:.xsd=-pimpl.o) \
+$(xsd:.xsd=-sskel.o) \
+$(xsd:.xsd=-simpl.o))
+
+dep := $(obj:.o=.o.d)
+
+xsde.l             := $(out_root)/libxsde/xsde/xsde.l
+xsde.l.cpp-options := $(out_root)/libxsde/xsde/xsde.l.cpp-options
+
+driver   := $(out_base)/driver
+test     := $(out_base)/.test
+dist     := $(out_base)/.dist
+dist-win := $(out_base)/.dist-win
+clean    := $(out_base)/.clean
+
+
+# Build.
+#
+$(driver): $(obj) $(xsde.l)
+
+$(obj) $(dep): $(xsde.l.cpp-options)
+
+genf := $(xsd:.xsd=.hxx) $(xsd:.xsd=.cxx) \
+        $(xsd:.xsd=-pskel.hxx) $(xsd:.xsd=-pskel.cxx) \
+        $(xsd:.xsd=-pimpl.hxx) $(xsd:.xsd=-pimpl.cxx) \
+        $(xsd:.xsd=-sskel.hxx) $(xsd:.xsd=-sskel.cxx) \
+        $(xsd:.xsd=-simpl.hxx) $(xsd:.xsd=-simpl.cxx)
+
+gen := $(addprefix $(out_base)/,$(genf))
+
+$(gen): $(out_root)/xsde/xsde
+$(gen): xsde := $(out_root)/xsde/xsde
+$(gen) $(dist) $(dist-win): xsde_options += --generate-parser \
+--generate-serializer --generate-aggregate --generate-clone \
+--custom-data complex
+
+$(call include-dep,$(dep))
+
+# Convenience alias for default target.
+#
+$(out_base)/: $(driver)
+
+
+# Test.
+#
+$(test): driver := $(driver)
+$(test): $(driver) $(src_base)/test-000.xml $(src_base)/test-000.std
+	$(call message,test $$1,$$1 $(src_base)/test-000.xml | diff -u $(src_base)/test-000.std -,$(driver))
+
+
+# Dist.
+#
+$(dist) $(dist-win): opt := -src $(src_base) -cmd cxx-hybrid -xsd "$(xsd)" \
+-cxx "$(cxx)" -gen "$(genf)" -opt "$(xsde_options)" -out $(dist_prefix)
+
+$(dist):
+	$(call message,install $(src_base),$(scf_root)/dist $(opt))
+
+$(dist-win):
+	$(call message,install $(src_base),$(scf_root)/dist -win $(opt))
+
+
+# Clean.
+#
+$(clean): $(driver).o.clean                                \
+  $(addsuffix .cxx.clean,$(obj))                           \
+  $(addsuffix .cxx.clean,$(dep))                           \
+  $(addprefix $(out_base)/,$(xsd:.xsd=.cxx.xsd.clean))
+
+
+# Generated .gitignore.
+#
+ifeq ($(out_base),$(src_base))
+$(gen): | $(out_base)/.gitignore
+$(driver): | $(out_base)/.gitignore
+
+$(out_base)/.gitignore: files := driver $(genf)
+$(clean): $(out_base)/.gitignore.clean
+
+$(call include,$(bld_root)/git/gitignore.make)
+endif
+
+
+# How to.
+#
+$(call include,$(bld_root)/cxx/o-e.make)
+$(call include,$(bld_root)/cxx/cxx-o.make)
+$(call include,$(bld_root)/cxx/cxx-d.make)
+$(call include,$(scf_root)/xsde/hybrid/xsd-cxx.make)
+
+
+# Dependencies.
+#
+$(call import,$(src_root)/xsde/makefile)
+$(call import,$(src_root)/libxsde/xsde/makefile)
diff --git a/tests/cxx/hybrid/clone/test-000.std b/tests/cxx/hybrid/clone/test-000.std
new file mode 100644
index 0000000..f50ea2f
--- /dev/null
+++ b/tests/cxx/hybrid/clone/test-000.std
@@ -0,0 +1,71 @@
+<t:root xmlns:t="test">
+  <complex af="123" afixed="abc" av="abc def">
+    <f>123</f>
+    <v>abc def ghq</v>
+    <of>123</of>
+    <ov>abc def ghq</ov>
+    <pod>1</pod>
+    <pod>2</pod>
+    <pod>3</pod>
+    <fix>
+      <x>1</x>
+      <y>1</y>
+    </fix>
+    <fix>
+      <x>2</x>
+      <y>2</y>
+    </fix>
+    <fix>
+      <x>3</x>
+      <y>3</y>
+    </fix>
+    <var>a1 b1 c1</var>
+    <var>a2 b2 c2</var>
+    <var>a3 b3 c3</var>
+    <str>aaa</str>
+    <str>bbb</str>
+    <str>ccc</str>
+    <cv>abc def ghq</cv>
+  </complex>
+  <all>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <of>123</of>
+    <ov>abc def ghq</ov>
+  </all>
+  <sequence>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <c1v>abc def ghq</c1v>
+    <c2f>123</c2f>
+  </sequence>
+  <choice>
+    <cf>123</cf>
+  </choice>
+  <choice>
+    <cv>abc def ghq</cv>
+  </choice>
+  <choice>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <f>123</f>
+    <v>abc def ghq</v>
+  </choice>
+  <fixder>
+    <x>1</x>
+    <y>1</y>
+    <v>abc def ghq</v>
+  </fixder>
+  <varder>
+    <x>1</x>
+    <y>abc def ghq</y>
+    <f>123</f>
+  </varder>
+  <strder v="abc def ghq">str str</strder>
+  <list>abc def ghq</list>
+  <union>abc</union>
+  <enum>c</enum>
+  <enumder>b</enumder>
+</t:root>
\ No newline at end of file
diff --git a/tests/cxx/hybrid/clone/test-000.xml b/tests/cxx/hybrid/clone/test-000.xml
new file mode 100644
index 0000000..c10c1b7
--- /dev/null
+++ b/tests/cxx/hybrid/clone/test-000.xml
@@ -0,0 +1,79 @@
+<t:root xmlns:t="test">
+  <complex af="123" av="abc def">
+    <f>123</f>
+    <v>abc def ghq</v>
+    <of>123</of>
+    <ov>abc def ghq</ov>
+
+    <pod>1</pod>
+    <pod>2</pod>
+    <pod>3</pod>
+
+    <fix><x>1</x><y>1</y></fix>
+    <fix><x>2</x><y>2</y></fix>
+    <fix><x>3</x><y>3</y></fix>
+
+    <var>a1 b1 c1</var>
+    <var>a2 b2 c2</var>
+    <var>a3 b3 c3</var>
+
+    <str>aaa</str>
+    <str>bbb</str>
+    <str>ccc</str>
+
+    <cv>abc def ghq</cv>
+  </complex>
+
+  <all>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <of>123</of>
+    <ov>abc def ghq</ov>
+  </all>
+
+  <sequence>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <f>123</f>
+    <v>abc def ghq</v>
+
+    <c1v>abc def ghq</c1v>
+
+    <c2f>123</c2f>
+  </sequence>
+
+  <choice>
+    <cf>123</cf>
+  </choice>
+
+  <choice>
+    <cv>abc def ghq</cv>
+  </choice>
+
+  <choice>
+    <f>123</f>
+    <v>abc def ghq</v>
+    <f>123</f>
+    <v>abc def ghq</v>
+  </choice>
+
+  <fixder>
+    <x>1</x>
+    <y>1</y>
+    <v>abc def ghq</v>
+  </fixder>
+
+  <varder>
+    <x>1</x>
+    <y>abc def ghq</y>
+    <f>123</f>
+  </varder>
+
+  <strder v="abc def ghq">str str</strder>
+
+  <list>abc def ghq</list>
+  <union>abc</union>
+  <enum>c</enum>
+  <enumder>b</enumder>
+
+</t:root>
diff --git a/tests/cxx/hybrid/clone/test.xsd b/tests/cxx/hybrid/clone/test.xsd
new file mode 100644
index 0000000..cc4bc12
--- /dev/null
+++ b/tests/cxx/hybrid/clone/test.xsd
@@ -0,0 +1,148 @@
+<?xml version="1.0"?>
+<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:t="test" targetNamespace="test">
+
+  <complexType name="fix">
+    <sequence>
+      <element name="x" type="int"/>
+      <element name="y" type="int"/>
+    </sequence>
+  </complexType>
+
+  <complexType name="var">
+    <sequence>
+      <element name="x" type="int"/>
+      <element name="y" type="NMTOKENS"/>
+    </sequence>
+  </complexType>
+
+  <complexType name="all">
+    <all minOccurs="0">
+      <element name="f" type="int"/>
+      <element name="v" type="NMTOKENS"/>
+      <element name="of" type="int" minOccurs="0"/>
+      <element name="ov" type="NMTOKENS" minOccurs="0"/>
+    </all>
+  </complexType>
+
+  <complexType name="sequence">
+    <sequence>
+      <sequence maxOccurs="unbounded">
+        <element name="f" type="int"/>
+        <element name="v" type="NMTOKENS"/>
+      </sequence>
+      <choice>
+        <element name="c1f" type="int"/>
+        <element name="c1v" type="NMTOKENS"/>
+      </choice>
+      <choice minOccurs="0">
+        <element name="c2f" type="int"/>
+        <element name="c2v" type="NMTOKENS"/>
+      </choice>
+    </sequence>
+  </complexType>
+
+  <complexType name="choice">
+    <choice>
+      <choice>
+        <element name="cf" type="int"/>
+        <element name="cv" type="NMTOKENS"/>
+      </choice>
+      <sequence maxOccurs="unbounded">
+        <element name="f" type="int"/>
+        <element name="v" type="NMTOKENS"/>
+      </sequence>
+    </choice>
+  </complexType>
+
+  <complexType name="complex">
+    <sequence>
+      <element name="f" type="int"/>
+      <element name="v" type="NMTOKENS"/>
+      <element name="of" type="int" minOccurs="0"/>
+      <element name="ov" type="NMTOKENS" minOccurs="0"/>
+      <element name="pod" type="int" maxOccurs="unbounded"/>
+      <element name="fix" type="t:var" maxOccurs="unbounded"/>
+      <element name="var" type="NMTOKENS" maxOccurs="unbounded"/>
+      <element name="str" type="string" maxOccurs="unbounded"/>
+      <choice>
+        <element name="cf" type="int"/>
+        <element name="cv" type="NMTOKENS"/>
+      </choice>
+    </sequence>
+    <attribute name="af" type="int" use="required"/>
+    <attribute name="av" type="NMTOKENS" default="abc"/>
+    <attribute name="afixed" type="NMTOKENS" default="abc"/>
+  </complexType>
+
+  <complexType name="fixder">
+    <complexContent>
+      <extension base="t:fix">
+        <sequence>
+          <element name="v" type="NMTOKENS"/>
+        </sequence>
+      </extension>
+    </complexContent>
+  </complexType>
+
+  <complexType name="varder">
+    <complexContent>
+      <extension base="t:var">
+        <sequence>
+          <element name="f" type="int"/>
+        </sequence>
+      </extension>
+    </complexContent>
+  </complexType>
+
+  <complexType name="strder">
+    <simpleContent>
+      <extension base="string">
+        <attribute name="v" type="NMTOKENS"/>
+      </extension>
+    </simpleContent>
+  </complexType>
+
+  <simpleType name="list">
+    <list itemType="string"/>
+  </simpleType>
+
+  <simpleType name="union">
+    <union memberTypes="int string"/>
+  </simpleType>
+
+  <simpleType name="enum">
+    <restriction base="string">
+      <enumeration value="a"/>
+      <enumeration value="b"/>
+      <enumeration value="c"/>
+    </restriction>
+  </simpleType>
+
+  <simpleType name="enumder">
+    <restriction base="t:enum">
+      <enumeration value="a"/>
+      <enumeration value="b"/>
+    </restriction>
+  </simpleType>
+
+  <complexType name="type">
+    <sequence>
+      <element name="complex" type="t:complex"/>
+      <element name="all" type="t:all"/>
+      <element name="sequence" type="t:sequence"/>
+      <element name="choice" type="t:choice" maxOccurs="unbounded"/>
+
+      <element name="fixder" type="t:fixder"/>
+      <element name="varder" type="t:varder"/>
+      <element name="strder" type="t:strder"/>
+
+      <element name="list" type="t:list"/>
+      <element name="union" type="t:union"/>
+      <element name="enum" type="t:enum"/>
+      <element name="enumder" type="t:enumder"/>
+    </sequence>
+  </complexType>
+
+  <element name="root" type="t:type"/>
+
+</schema>
diff --git a/tests/cxx/hybrid/makefile b/tests/cxx/hybrid/makefile
index 8fb3f3f..88d89a2 100644
--- a/tests/cxx/hybrid/makefile
+++ b/tests/cxx/hybrid/makefile
@@ -10,7 +10,8 @@ include $(dir $(lastword $(MAKEFILE_LIST)))../../../build/bootstrap.make
 #
 
 all_tests := sequences polymorphism iterator built-in default enumeration \
-iso8859-1 list recursive test-template union binary/cdr binary/xdr choice
+iso8859-1 list recursive test-template union binary/cdr binary/xdr choice \
+clone
 
 build_tests := sequences
 
@@ -40,7 +41,7 @@ build_tests += binary/xdr
 endif
 
 ifeq ($(xsde_parser_validation),y)
-build_tests += choice recursive
+build_tests += choice recursive clone
 endif
 
 endif # xsde_iostream
diff --git a/xsde/cxx/hybrid/cli.hxx b/xsde/cxx/hybrid/cli.hxx
index 5de1692..5d691d6 100644
--- a/xsde/cxx/hybrid/cli.hxx
+++ b/xsde/cxx/hybrid/cli.hxx
@@ -36,6 +36,7 @@ namespace CXX
       extern Key suppress_serializer_val;
       extern Key omit_default_attributes;
       extern Key suppress_enum;
+      extern Key generate_clone;
       extern Key generate_detach;
       extern Key generate_insertion;
       extern Key generate_extraction;
@@ -127,6 +128,7 @@ namespace CXX
         suppress_serializer_val,  Boolean,
         omit_default_attributes,  Boolean,
         suppress_enum,            Boolean,
+        generate_clone,           Boolean,
         generate_detach,          Boolean,
         generate_insertion,       Cult::Containers::Vector<NarrowString>,
         generate_extraction,      Cult::Containers::Vector<NarrowString>,
diff --git a/xsde/cxx/hybrid/elements.cxx b/xsde/cxx/hybrid/elements.cxx
index fe5c97e..b8c109a 100644
--- a/xsde/cxx/hybrid/elements.cxx
+++ b/xsde/cxx/hybrid/elements.cxx
@@ -40,6 +40,7 @@ namespace CXX
           poly_code (ops.value<CLI::generate_polymorphic> ()),
           poly_runtime (poly_code || ops.value<CLI::runtime_polymorphic> ()),
           reset (!ops.value<CLI::suppress_reset> ()),
+          clone (ops.value<CLI::generate_clone> ()),
           detach (ops.value<CLI::generate_detach> ()),
           mixin (ops.value<CLI::reuse_style_mixin> ()),
           tiein (!mixin),
diff --git a/xsde/cxx/hybrid/elements.hxx b/xsde/cxx/hybrid/elements.hxx
index 60211e8..7bd8bd1 100644
--- a/xsde/cxx/hybrid/elements.hxx
+++ b/xsde/cxx/hybrid/elements.hxx
@@ -45,6 +45,7 @@ namespace CXX
             poly_code (c.poly_code),
             poly_runtime (c.poly_runtime),
             reset (c.reset),
+            clone (c.clone),
             detach (c.detach),
             typeinfo (c.typeinfo),
             mixin (c.mixin),
@@ -76,6 +77,7 @@ namespace CXX
             poly_code (c.poly_code),
             poly_runtime (c.poly_runtime),
             reset (c.reset),
+            clone (c.clone),
             detach (c.detach),
             typeinfo (c.typeinfo),
             mixin (c.mixin),
@@ -594,6 +596,7 @@ namespace CXX
       Boolean poly_code;
       Boolean poly_runtime;
       Boolean reset;
+      Boolean clone;
       Boolean detach;
       Boolean typeinfo;
       Boolean mixin;
@@ -2060,6 +2063,73 @@ namespace CXX
 
     //
     //
+    struct TypeClone: TypeOpsBase, Context
+    {
+      TypeClone (Context& c)
+          : Context (c)
+      {
+      }
+
+      // Copy member from 'this' to 'c'.
+      //
+      Void
+      dispatch (SemanticGraph::Node& type, SemanticGraph::Member& member)
+      {
+        member_ = &member;
+        Traversal::NodeBase::dispatch (type);
+      }
+
+    protected:
+      virtual Void
+      type (SemanticGraph::Type& t)
+      {
+        String const& name (ename (*member_));
+
+        os << "{"
+           << fq_name (t) << "* m = this->" << name << " ()._clone ();";
+
+        if (!exceptions)
+          os << endl
+             << "if (m == 0)" << endl
+             << "return false;"
+             << endl;
+
+        os << "c." << name << " (m);"
+           << "}";
+      }
+
+      virtual Void
+      fund_type (SemanticGraph::Type& t)
+      {
+        type (t);
+      }
+
+      virtual Void
+      string_type (SemanticGraph::Type&)
+      {
+        // We can only get here if STL is disabled.
+        //
+        String const& name (ename (*member_));
+
+        os << "{"
+           << "char* m = ::xsde::cxx::strdupx (this->" << name << " ());";
+
+        if (!exceptions)
+          os << endl
+             << "if (m == 0)" << endl
+             << "return false;"
+             << endl;
+
+        os << "c." << name << " (m);"
+           << "}";
+      }
+
+    private:
+      SemanticGraph::Member* member_;
+    };
+
+    //
+    //
     struct TypeForward: Traversal::Type, Context
     {
       TypeForward (Context& c)
diff --git a/xsde/cxx/hybrid/generator.cxx b/xsde/cxx/hybrid/generator.cxx
index 0ccbb91..ee39079 100644
--- a/xsde/cxx/hybrid/generator.cxx
+++ b/xsde/cxx/hybrid/generator.cxx
@@ -124,6 +124,7 @@ namespace CXX
       extern Key suppress_serializer_val  = "suppress-serializer-val";
       extern Key omit_default_attributes  = "omit-default-attributes";
       extern Key suppress_enum            = "suppress-enum";
+      extern Key generate_clone           = "generate-clone";
       extern Key generate_detach          = "generate-detach";
       extern Key generate_insertion       = "generate-insertion";
       extern Key generate_extraction      = "generate-extraction";
@@ -271,6 +272,11 @@ namespace CXX
       << " enumeration to C++ enum mapping."
       << endl;
 
+    e << "--generate-clone" << endl
+      << " Generate clone functions for variable-length\n"
+      << " types."
+      << endl;
+
     e << "--generate-detach" << endl
       << " Generate detach functions for elements and\n"
       << " attributes of variable-length types."
diff --git a/xsde/cxx/hybrid/tree-header.cxx b/xsde/cxx/hybrid/tree-header.cxx
index 7e748bb..c596ab0 100644
--- a/xsde/cxx/hybrid/tree-header.cxx
+++ b/xsde/cxx/hybrid/tree-header.cxx
@@ -112,6 +112,13 @@ namespace CXX
                << name << " (" << vt << ");"
                << endl;
 
+            // _clone
+            //
+            if (!fl && clone)
+              os << (poly ? "virtual " : "") << name << "*" << endl
+                 << "_clone () const;"
+                 << endl;
+
             // value (value_type)
             //
             if (!base_enum)
@@ -197,6 +204,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (!fl && clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << name << "&) const;"
+                 << endl;
+
             if (!base_enum || cd)
               os << "private:" << endl;
 
@@ -274,15 +288,22 @@ namespace CXX
             // c-tor
             //
             os << "public:" << endl
-               << name << " ();";
+               << name << " ();"
+               << endl;
+
+            // _clone
+            //
+            if (clone)
+              os << (poly ? "virtual " : "") << name << "*" << endl
+                 << "_clone () const;"
+                 << endl;
 
             // d-tor
             //
             if (poly)
               os << "virtual" << endl
-                 << "~" << name << " ();";
-
-            os << endl;
+                 << "~" << name << " ();"
+                 << endl;
 
             // Custom data.
             //
@@ -335,6 +356,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << name << "&) const;"
+                 << endl;
+
             if (cd)
             {
               os << "private:" << endl
@@ -401,7 +429,15 @@ namespace CXX
 
             // c-tor
             //
-            os << name << " ();";
+            os << name << " ();"
+               << endl;
+
+            // _clone
+            //
+            if (!fl && clone)
+              os << (poly ? "virtual " : "") << name << "*" << endl
+                 << "_clone () const;"
+                 << endl;
 
             // d-tor
             //
@@ -521,6 +557,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (!fl && clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << name << "&) const;"
+                 << endl;
+
             if (stl)
             {
               os << "private:" << endl
@@ -634,7 +677,7 @@ namespace CXX
           belongs_ >> *this;
         }
 
-        // Type alignment ranking (the high the rank, the stricter
+        // Type alignment ranking (the higher the rank, the stricter
         // the alignment requirements):
         //
         // char      1
@@ -1315,7 +1358,7 @@ namespace CXX
         traverse (SemanticGraph::Attribute& a)
         {
           os << "// " << comment (a.name ()) << endl
-             << "// " << endl;
+             << "//" << endl;
 
           Boolean def (a.default_p ());
           Boolean fix (a.fixed_p ());
@@ -1413,7 +1456,7 @@ namespace CXX
         traverse (SemanticGraph::Element& e)
         {
           os << "// " << comment (e.name ()) << endl
-             << "// " << endl;
+             << "//" << endl;
 
           String const& name (ename (e));
           SemanticGraph::Type& t (e.type ());
@@ -1535,22 +1578,33 @@ namespace CXX
 
             os << "// " << comment (name) << " (" <<
               (fl ? "fixed-length" : "variable-length") << ")" << endl
-               << "// " << endl;
+               << "//" << endl;
 
             os << "class " << type
                << "{";
 
-            // c-tor & d-tor
+            // c-tor
             //
             os << "public:" << endl
                << type << " ();"
-               << "~" << type << " ();";
+               << endl;
+
+            // _clone
+            //
+            if (!fl && clone)
+              os << type << "*" << endl
+                 << "_clone () const;"
+                 << endl;
+
+            // d-tor
+            //
+            os << "~" << type << " ();"
+               << endl;
 
             // copy c-tor & operator=
             //
             if (!fl)
-              os << endl
-                 << "private:" << endl;
+              os << "private:" << endl;
 
             os << type << " (const " << type << "&);"
                << type << "& operator= (const " << type << "&);"
@@ -1596,6 +1650,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (!fl && clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << type << "&) const;"
+                 << endl;
+
             os << "private:" << endl;
 
             All::contains (a, contains_data_);
@@ -1739,22 +1800,33 @@ namespace CXX
 
             os << "// " << comment (name) << " (" <<
             (fl ? "fixed-length" : "variable-length") << ")" << endl
-             << "// " << endl;
+             << "//" << endl;
 
             os << "class " << type
                << "{";
 
-            // c-tor & d-tor
+            // c-tor
             //
             os << "public:" << endl
                << type << " ();"
-               << "~" << type << " ();";
+               << endl;
+
+            // _clone
+            //
+            if (!fl && clone)
+              os << type << "*" << endl
+                 << "_clone () const;"
+                 << endl;
+
+            // d-tor
+            //
+            os << "~" << type << " ();"
+               << endl;
 
             // copy c-tor & operator=
             //
             if (!fl)
-              os << endl
-                 << "private:" << endl;
+              os << "private:" << endl;
 
             os << type << " (const " << type << "&);"
                << type << "& operator= (const " << type << "&);"
@@ -1766,7 +1838,7 @@ namespace CXX
           else
           {
             os << "// " << comment (name) << endl
-               << "// " << endl;
+               << "//" << endl;
           }
 
           String const& arm_tag (earm_tag (c));
@@ -1838,6 +1910,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (!fl && clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << type << "&) const;"
+                 << endl;
+
             os << "private:" << endl
                << "union"
                << "{";
@@ -1967,22 +2046,33 @@ namespace CXX
 
           os << "// " << comment (name) << " (" <<
             (fl ? "fixed-length" : "variable-length") << ")" << endl
-             << "// " << endl;
+             << "//" << endl;
 
           os << "class " << type
              << "{";
 
-          // c-tor & d-tor
+          // c-tor
           //
           os << "public:" << endl
              << type << " ();"
-             << "~" << type << " ();";
+             << endl;
+
+          // _clone
+          //
+          if (!fl && clone)
+            os << type << "*" << endl
+               << "_clone () const;"
+               << endl;
+
+          // d-tor
+          //
+          os << "~" << type << " ();"
+             << endl;
 
           // copy c-tor & operator=
           //
           if (!fl)
-            os << endl
-               << "private:" << endl;
+            os << "private:" << endl;
 
           os << type << " (const " << type << "&);"
              << type << "& operator= (const " << type << "&);"
@@ -2056,6 +2146,13 @@ namespace CXX
                << endl;
           }
 
+          // _copy
+          //
+          if (!fl && clone)
+            os << (exceptions ? "void" : "bool") << endl
+               << "_copy (" << type << "&) const;"
+               << endl;
+
           os << "private:" << endl
              << "union"
              << "{";
@@ -2190,22 +2287,33 @@ namespace CXX
 
           os << "// " << comment (name) << " (" <<
             (fl ? "fixed-length" : "variable-length") << ")" << endl
-             << "// " << endl;
+             << "//" << endl;
 
           os << "class " << type
              << "{";
 
-          // c-tor & d-tor
+          // c-tor
           //
           os << "public:" << endl
              << type << " ();"
-             << "~" << type << " ();";
+             << endl;
+
+          // _clone
+          //
+          if (!fl && clone)
+            os << type << "*" << endl
+               << "_clone () const;"
+               << endl;
+
+          // d-tor
+          //
+          os << "~" << type << " ();"
+             << endl;
 
           // copy c-tor & operator=
           //
           if (!fl)
-            os << endl
-               << "private:" << endl;
+            os << "private:" << endl;
 
           os << type << " (const " << type << "&);"
              << type << "& operator= (const " << type << "&);"
@@ -2251,6 +2359,13 @@ namespace CXX
                << endl;
           }
 
+          // _copy
+          //
+          if (!fl && clone)
+            os << (exceptions ? "void" : "bool") << endl
+               << "_copy (" << type << "&) const;"
+               << endl;
+
           os << "private:" << endl;
 
           Sequence::contains (s, contains_data_);
@@ -2372,22 +2487,33 @@ namespace CXX
 
           os << "// " << comment (name) << " (" <<
             (fl ? "fixed-length" : "variable-length") << ")" << endl
-             << "// " << endl;
+             << "//" << endl;
 
           os << "class " << type
              << "{";
 
-          // c-tor & d-tor
+          // c-tor
           //
           os << "public:" << endl
              << type << " ();"
-             << "~" << type << " ();";
+             << endl;
+
+          // _clone
+          //
+          if (!fl && clone)
+            os << type << "*" << endl
+               << "_clone () const;"
+               << endl;
+
+          // d-tor
+          //
+          os << "~" << type << " ();"
+             << endl;
 
           // copy c-tor & operator=
           //
           if (!fl)
-            os << endl
-               << "private:" << endl;
+            os << "private:" << endl;
 
           os << type << " (const " << type << "&);"
              << type << "& operator= (const " << type << "&);"
@@ -2431,6 +2557,13 @@ namespace CXX
                << endl;
           }
 
+          // _copy
+          //
+          if (!fl && clone)
+            os << (exceptions ? "void" : "bool") << endl
+               << "_copy (" << type << "&) const;"
+               << endl;
+
           os << "private:" << endl;
 
           Sequence::contains (s, contains_data_);
@@ -2533,7 +2666,7 @@ namespace CXX
         Traversal::ContainsParticle& contains_data_;
       };
 
-      struct Complex : Traversal::Complex, Context
+      struct Complex: Traversal::Complex, Context
       {
         Complex (Context& c)
             : Context (c),
@@ -2646,20 +2779,28 @@ namespace CXX
             // c-tor
             //
             os << "public:" << endl
-               << name << " ();";
-
-            // d-tor
-            //
-            if (!restriction || poly)
-              os << (poly ? "virtual\n" : "") << "~" << name << " ();";
+               << name << " ();"
+               << endl;
 
             // copy c-tor & operator= (public)
             //
             if (fl && !restriction)
               os << name << " (const " << name << "&);"
-                 << name << "& operator= (const " << name << "&);";
+                 << name << "& operator= (const " << name << "&);"
+                 << endl;
 
-            os << endl;
+            // _clone
+            //
+            if (!fl && clone)
+              os << (poly ? "virtual " : "") << name << "*" << endl
+                 << "_clone () const;"
+                 << endl;
+
+            // d-tor
+            //
+            if (!restriction || poly)
+              os << (poly ? "virtual\n" : "") << "~" << name << " ();"
+                 << endl;
 
             if (!restriction)
             {
@@ -2720,6 +2861,13 @@ namespace CXX
                  << endl;
             }
 
+            // _copy
+            //
+            if (!fl && clone)
+              os << (exceptions ? "void" : "bool") << endl
+                 << "_copy (" << name << "&) const;"
+                 << endl;
+
             if (!restriction || cd)
               os << "private:" << endl;
 
diff --git a/xsde/cxx/hybrid/tree-source.cxx b/xsde/cxx/hybrid/tree-source.cxx
index 5887d32..33995c5 100644
--- a/xsde/cxx/hybrid/tree-source.cxx
+++ b/xsde/cxx/hybrid/tree-source.cxx
@@ -32,7 +32,10 @@ namespace CXX
       struct Enumeration: Traversal::Enumeration, Context
       {
         Enumeration (Context& c, Traversal::Complex& complex)
-            : Context (c), complex_ (complex), enumerator_ (c)
+            : Context (c),
+              complex_ (complex),
+              base_name_ (c, TypeName::base),
+              enumerator_ (c)
         {
           names_ >> enumerator_;
         }
@@ -129,6 +132,123 @@ namespace CXX
                  << "}";
             }
           }
+
+          // _clone
+          //
+          if (clone && !fixed_length (e))
+          {
+            //
+            // _copy
+            //
+
+            os << (exceptions ? "void " : "bool ") << name << "::" << endl
+               << "_copy (" << name << "& c) const"
+               << "{";
+
+            // Copy the base or enum value.
+            //
+            if (base_enum)
+            {
+              SemanticGraph::Type& b (e.inherits ().base ());
+
+              if (fixed_length (b))
+              {
+                os << "static_cast< ";
+                base_name_.dispatch (b);
+                os << "& > (c) = *this;";
+              }
+              else
+              {
+                os << "const ";
+                base_name_.dispatch (b);
+                os << "& b = *this;";
+
+                if (exceptions)
+                  os << "b._copy (c);";
+                else
+                  os << "if (!b._copy (c))" << endl
+                     << "return false;"
+                     << endl;
+              }
+            }
+            else
+            {
+              String const& m (ec.get<String> ("value-member"));
+              os << "c." << m << " = this->" << m << ";";
+            }
+
+            // Copy custom data.
+            //
+            if (ec.count ("cd-name"))
+            {
+              String const& m (ecd_member (e));
+
+              if (exceptions)
+                os << "this->" << m << ".copy (c." << m << ");";
+              else
+                os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            if (!exceptions)
+              os << "return true;";
+
+            os << "}";
+
+            //
+            // _clone
+            //
+
+            os << name << "* "  << name << "::" << endl
+               << "_clone () const"
+               << "{";
+
+            if (!custom_alloc)
+              os << name << "* c = new " << name << ";";
+            else
+              os << name << "* c = static_cast< " << name << "* > (" << endl
+                 << "::xsde::cxx::alloc (sizeof (" << name << ")));";
+
+            if (!exceptions)
+              os << endl
+                 << "if (c == 0)" << endl
+                 << "return 0;"
+                 << endl;
+
+            if (custom_alloc)
+            {
+              if (exceptions)
+                os << "::xsde::cxx::alloc_guard ag (c);";
+
+              os << "new (c) " << name << ";";
+
+              if (exceptions)
+                os << "ag.release ();";
+            }
+
+            if (exceptions)
+              os << "::xsde::cxx::guard< " << name << " > g (c);"
+                 << "this->_copy (*c);"
+                 << "g.release ();";
+            else
+            {
+              os << "if (!this->_copy (*c))"
+                 << "{";
+
+              if (!custom_alloc)
+                os << "delete c;";
+              else
+                os << "c->~" << name << " ();"
+                   << "::xsde::cxx::free (c);";
+
+              os << "return 0;"
+                 << "}";
+            }
+
+            os << "return c;"
+               << "}";
+          }
         }
 
         virtual Void
@@ -140,6 +260,8 @@ namespace CXX
       private:
         Traversal::Complex& complex_;
 
+        TypeName base_name_;
+
         Traversal::Names names_;
         Enumerator enumerator_;
       };
@@ -147,7 +269,7 @@ namespace CXX
       struct List : Traversal::List, Context
       {
         List (Context& c)
-            : Context (c)
+            : Context (c), base_name_ (c, TypeName::seq)
         {
         }
 
@@ -162,12 +284,16 @@ namespace CXX
           if (!name)
             return;
 
-          if (polymorphic (l))
-          {
+          Boolean poly (polymorphic (l));
+          SemanticGraph::Context& lc (l.context ());
+
+          if (poly || clone)
             os << "// " << comment (l.name ()) << endl
                << "//" << endl
                << endl;
 
+          if (poly)
+          {
             // d-tor
             //
             os << name << "::" << endl
@@ -214,7 +340,108 @@ namespace CXX
                  << "}";
             }
           }
+
+          // _clone
+          //
+          if (clone)
+          {
+            //
+            // _copy
+            //
+
+            os << (exceptions ? "void " : "bool ") << name << "::" << endl
+               << "_copy (" << name << "& c) const"
+               << "{";
+
+            // Copy the base.
+            //
+            os << "const ";
+            base_name_.dispatch (l.argumented ().type ());
+            os << "& b = *this;";
+
+            if (exceptions)
+              os << "b.copy (c);";
+            else
+              os << "if (b.copy (c))" << endl
+                 << "return false;"
+                 << endl;
+
+            // Copy custom data.
+            //
+            if (lc.count ("cd-name"))
+            {
+              String const& m (ecd_member (l));
+
+              if (exceptions)
+                os << "this->" << m << ".copy (c." << m << ");";
+              else
+                os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            if (!exceptions)
+              os << "return true;";
+
+            os << "}";
+
+            //
+            // _clone
+            //
+
+            os << name << "* "  << name << "::" << endl
+               << "_clone () const"
+               << "{";
+
+            if (!custom_alloc)
+              os << name << "* c = new " << name << ";";
+            else
+              os << name << "* c = static_cast< " << name << "* > (" << endl
+                 << "::xsde::cxx::alloc (sizeof (" << name << ")));";
+
+            if (!exceptions)
+              os << endl
+                 << "if (c == 0)" << endl
+                 << "return 0;"
+                 << endl;
+
+            if (custom_alloc)
+            {
+              if (exceptions)
+                os << "::xsde::cxx::alloc_guard ag (c);";
+
+              os << "new (c) " << name << ";";
+
+              if (exceptions)
+                os << "ag.release ();";
+            }
+
+            if (exceptions)
+              os << "::xsde::cxx::guard< " << name << " > g (c);"
+                 << "this->_copy (*c);"
+                 << "g.release ();";
+            else
+            {
+              os << "if (!this->_copy (*c))"
+                 << "{";
+
+              if (!custom_alloc)
+                os << "delete c;";
+              else
+                os << "c->~" << name << " ();"
+                   << "::xsde::cxx::free (c);";
+
+              os << "return 0;"
+                 << "}";
+            }
+
+            os << "return c;"
+               << "}";
+          }
         }
+
+      private:
+        TypeName base_name_;
       };
 
       //
@@ -238,13 +465,14 @@ namespace CXX
             return;
 
           Boolean poly (polymorphic (u));
+          SemanticGraph::Context& uc (u.context ());
+
+          os << "// " << comment (u.name ()) << endl
+             << "//" << endl
+             << endl;
 
           if (!stl || poly)
           {
-            os << "// " << comment (u.name ()) << endl
-               << "//" << endl
-               << endl;
-
             // d-tor
             //
             os << name << "::" << endl
@@ -302,6 +530,108 @@ namespace CXX
                  << "}";
             }
           }
+
+          // _clone
+          //
+          if (clone && !fixed_length (u))
+          {
+            //
+            // _copy
+            //
+
+            os << (exceptions ? "void " : "bool ") << name << "::" << endl
+               << "_copy (" << name << "& c) const"
+               << "{";
+
+            // Copy the value.
+            //
+            String const& m (uc.get<String> ("value-member"));
+
+            if (stl)
+              os << "c." << m << " = this->" << m << ";";
+            else
+            {
+              os << "c." << m << " = ::xsde::cxx::strdupx (this->" << m << ");";
+
+              if (!exceptions)
+                os << endl
+                   << "if (c." << m << " == 0)" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            // Copy custom data.
+            //
+            if (uc.count ("cd-name"))
+            {
+              String const& m (ecd_member (u));
+
+              if (exceptions)
+                os << "this->" << m << ".copy (c." << m << ");";
+              else
+                os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            if (!exceptions)
+              os << "return true;";
+
+            os << "}";
+
+            //
+            // _clone
+            //
+
+            os << name << "* "  << name << "::" << endl
+               << "_clone () const"
+               << "{";
+
+            if (!custom_alloc)
+              os << name << "* c = new " << name << ";";
+            else
+              os << name << "* c = static_cast< " << name << "* > (" << endl
+                 << "::xsde::cxx::alloc (sizeof (" << name << ")));";
+
+            if (!exceptions)
+              os << endl
+                 << "if (c == 0)" << endl
+                 << "return 0;"
+                 << endl;
+
+            if (custom_alloc)
+            {
+              if (exceptions)
+                os << "::xsde::cxx::alloc_guard ag (c);";
+
+              os << "new (c) " << name << ";";
+
+              if (exceptions)
+                os << "ag.release ();";
+            }
+
+            if (exceptions)
+              os << "::xsde::cxx::guard< " << name << " > g (c);"
+                 << "this->_copy (*c);"
+                 << "g.release ();";
+            else
+            {
+              os << "if (!this->_copy (*c))"
+                 << "{";
+
+              if (!custom_alloc)
+                os << "delete c;";
+              else
+                os << "c->~" << name << " ();"
+                   << "::xsde::cxx::free (c);";
+
+              os << "return 0;"
+                 << "}";
+            }
+
+            os << "return c;"
+               << "}";
+          }
         }
       };
 
@@ -1379,6 +1709,324 @@ namespace CXX
       };
 
       //
+      // Clone.
+      //
+
+      struct AttributeClone: Traversal::Attribute, Context
+      {
+        AttributeClone (Context& c)
+            : Context (c), clone_ (c)
+        {
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Attribute& a)
+        {
+          if (!a.fixed_p ())
+          {
+            String const& name (ename (a));
+            SemanticGraph::Type& t (a.type ());
+
+            Boolean opt (a.optional_p () && !a.default_p ());
+
+            if (opt)
+              os << "if (this->" << epresent (a) << " ())";
+
+            if (fixed_length (t))
+              os << (opt ? "\n" : "")
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+              clone_.dispatch (t, a);
+          }
+        }
+
+      private:
+        TypeClone clone_;
+      };
+
+
+      struct ElementClone: Traversal::Element, Context
+      {
+        ElementClone (Context& c)
+            : Context (c), clone_ (c)
+        {
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Element& e)
+        {
+          String const& name (ename (e));
+
+          if (e.max () != 1)
+          {
+            if (exceptions)
+              os << "this->" << name << " ().copy (c." << name << " ());"
+                 << endl;
+            else
+              os << "if (this->" << name << " ().copy (c." << name << " ()))" << endl
+                 << "return false;"
+                 << endl;
+          }
+          else
+          {
+            SemanticGraph::Type& t (e.type ());
+
+            Boolean opt (e.min () == 0);
+
+            if (opt)
+              os << "if (this->" << epresent (e) << " ())";
+
+            if (fixed_length (t))
+              os << (opt ? "\n" : "")
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+              clone_.dispatch (t, e);
+          }
+        }
+
+      private:
+        TypeClone clone_;
+      };
+
+      struct AllClone: Traversal::All, Context
+      {
+        AllClone (Context& c)
+            : Context (c)
+        {
+        }
+
+        virtual Void
+        traverse (SemanticGraph::All& a)
+        {
+          // For the all compositor, maxOccurs=1 and minOccurs={0,1}
+          // and it can only contain particles.
+          //
+          if (a.min () == 0)
+          {
+            String const& name (ename (a));
+
+            os << "if (this->" << epresent (a) << " ())";
+
+            if (fixed_length (a))
+              os << endl
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+            {
+              os << "{"
+                 << etype (a) << "* m = this->" << name << " ()._clone ();";
+
+              if (!exceptions)
+                os << endl
+                   << "if (m == 0)" << endl
+                   << "return false;"
+                   << endl;
+
+              os << "c." << name << " (m);"
+                 << "}";
+            }
+          }
+          else
+            All::contains (a);
+        }
+      };
+
+      struct SequenceInSequenceClone: Traversal::Sequence, Context
+      {
+        SequenceInSequenceClone (Context& c)
+            : Context (c)
+        {
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Sequence& s)
+        {
+          if (s.max () != 1)
+          {
+            String const& name (ename (s));
+
+            if (exceptions)
+              os << "this->" << name << " ().copy (c." << name << " ());"
+                 << endl;
+            else
+              os << "if (this->" << name << " ().copy (c." << name << " ()))" << endl
+                 << "return false;"
+                 << endl;
+          }
+          else if (s.min () == 0)
+          {
+            String const& name (ename (s));
+
+            os << "if (this->" << epresent (s) << " ())";
+
+            if (fixed_length (s))
+              os << endl
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+            {
+              os << "{"
+                 << etype (s) << "* m = this->" << name << " ()._clone ();";
+
+              if (!exceptions)
+                os << endl
+                   << "if (m == 0)" << endl
+                   << "return false;"
+                   << endl;
+
+              os << "c." << name << " (m);"
+                 << "}";
+            }
+          }
+          else
+            Sequence::contains (s);
+        }
+      };
+
+      struct ParticleInChoiceClone: ElementClone, Traversal::Compositor
+      {
+        ParticleInChoiceClone (Context& c)
+            : ElementClone (c)
+        {
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Element& e)
+        {
+          os << "case " << etag (e) << ":"
+             << "{";
+
+          ElementClone::traverse (e);
+
+          os << "break;"
+             << "}";
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Compositor& c)
+        {
+          // In choice there are no inline compositors.
+          //
+          os << "case " << etag (c) << ":"
+             << "{";
+
+          String const& name (ename (c));
+
+          if (c.max () != 1)
+          {
+            if (exceptions)
+              os << "this->" << name << " ().copy (c." << name << " ());";
+            else
+              os << "if (this->" << name << " ().copy (c." << name << " ()))" << endl
+                 << "return false;";
+          }
+          else
+          {
+            Boolean opt (c.min () == 0);
+
+            if (opt)
+              os << "if (this->" << epresent (c) << " ())";
+
+            if (fixed_length (c))
+              os << (opt ? "\n" : "")
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+            {
+              os << "{"
+                 << etype (c) << "* m = this->" << name << " ()._clone ();";
+
+              if (!exceptions)
+                os << endl
+                   << "if (m == 0)" << endl
+                   << "return false;"
+                   << endl;
+
+              os << "c." << name << " (m);"
+                 << "}";
+            }
+          }
+
+          os << "break;"
+             << "}";
+        }
+      };
+
+      struct ChoiceInSequenceClone: Traversal::Choice, Context
+      {
+        ChoiceInSequenceClone (Context& c)
+            : Context (c), particle_ (c)
+        {
+          contains_particle_ >> particle_;
+        }
+
+        virtual Void
+        traverse (SemanticGraph::Choice& c)
+        {
+          if (c.max () != 1)
+          {
+            String const& name (ename (c));
+
+            if (exceptions)
+              os << "this->" << name << " ().copy (c." << name << " ());"
+                 << endl;
+            else
+              os << "if (this->" << name << " ().copy (c." << name << " ()))" << endl
+                 << "return false;"
+                 << endl;
+          }
+          else if (c.min () == 0)
+          {
+            String const& name (ename (c));
+
+            os << "if (this->" << epresent (c) << " ())";
+
+            if (fixed_length (c))
+              os << endl
+                 << "c." << name << " (this->" << name << " ());"
+                 << endl;
+            else
+            {
+              os << "{"
+                 << etype (c) << "* m = this->" << name << " ()._clone ();";
+
+              if (!exceptions)
+                os << endl
+                   << "if (m == 0)" << endl
+                   << "return false;"
+                   << endl;
+
+              os << "c." << name << " (m);"
+                 << "}";
+            }
+          }
+          else
+          {
+            // Inline choice.
+            //
+            String const& arm (earm (c));
+
+            os << "c." << arm << " (this->" << arm << " ());"
+               << endl
+               << "switch (this->" << arm << " ())"
+               << "{";
+
+            Choice::contains (c, contains_particle_);
+
+            os << "default:" << endl
+               << "break;"
+               << "}";
+          }
+        }
+
+      private:
+        ParticleInChoiceClone particle_;
+        Traversal::ContainsParticle contains_particle_;
+      };
+
+      //
       // Nested classes.
       //
 
@@ -1388,12 +2036,14 @@ namespace CXX
              Traversal::ContainsParticle& contains_ctor,
              Traversal::ContainsParticle& contains_dtor,
              Traversal::ContainsParticle& contains_copy,
-             Traversal::ContainsParticle& contains_assign)
+             Traversal::ContainsParticle& contains_assign,
+             Traversal::ContainsParticle& contains_clone)
             : Context (c),
               contains_ctor_ (contains_ctor),
               contains_dtor_ (contains_dtor),
               contains_copy_ (contains_copy),
-              contains_assign_ (contains_assign)
+              contains_assign_ (contains_assign),
+              contains_clone_ (contains_clone)
         {
         }
 
@@ -1403,57 +2053,147 @@ namespace CXX
           // For the all compositor, maxOccurs=1 and minOccurs={0,1}
           // and it can only contain particles.
           //
-          if (a.min () == 0)
-          {
-            String const& type (etype (a));
-            String const& scope (Context::scope (a));
+          if (a.min () != 0)
+            return;
+
+          Boolean fl (fixed_length (a));
+          String const& type (etype (a));
+          String const& scope (Context::scope (a));
+
+          // c-tor
+          //
+          os << scope << "::" << type << "::" << endl
+             << type << " ()"
+             << "{";
+
+          All::contains (a, contains_ctor_);
+
+          os << "}";
 
-            // c-tor
+          // d-tor
+          //
+          os << scope << "::" << type << "::" << endl
+             << "~" << type << " ()"
+             << "{";
+
+          All::contains (a, contains_dtor_);
+
+          os << "}";
+
+          if (fl)
+          {
+            // copy c-tor
             //
             os << scope << "::" << type << "::" << endl
-               << type << " ()"
-               << "{";
+               << type << " (const " << type << "& x)"
+               << "{"
+               << "XSDE_UNUSED (x);";
 
-            All::contains (a, contains_ctor_);
+            All::contains (a, contains_copy_);
 
             os << "}";
 
-            // d-tor
+            // operator=
             //
-            os << scope << "::" << type << "::" << endl
-               << "~" << type << " ()"
+            os << scope << "::" << type << "& " << scope << "::" <<
+              type << "::" << endl
+               << "operator= (const " << type << "& x)"
+               << "{"
+               << "XSDE_UNUSED (x);";
+
+            All::contains (a, contains_assign_);
+
+            os << "return *this;"
+               << "}";
+          }
+
+          // _clone
+          //
+          if (!fl && clone)
+          {
+            //
+            // _copy
+            //
+
+            os << (exceptions ? "void " : "bool ") << scope << "::" <<
+              type << "::" << endl
+               << "_copy (" << type << "& c) const"
                << "{";
 
-            All::contains (a, contains_dtor_);
+            All::contains (a, contains_clone_);
+
+            // Copy custom data.
+            //
+            if (a.context ().count ("cd-name"))
+            {
+              String const& m (ecd_member (a));
+
+              if (exceptions)
+                os << "this->" << m << ".copy (c." << m << ");";
+              else
+                os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            if (!exceptions)
+              os << "return true;";
 
             os << "}";
 
-            if (fixed_length (a))
+            //
+            // _clone
+            //
+
+            os << scope << "::" << type << "* " << scope << "::" <<
+              type << "::" << endl
+               << "_clone () const"
+               << "{";
+
+            if (!custom_alloc)
+              os << type << "* c = new " << type << ";";
+            else
+              os << type << "* c = static_cast< " << type << "* > (" << endl
+                 << "::xsde::cxx::alloc (sizeof (" << type << ")));";
+
+            if (!exceptions)
+              os << endl
+                 << "if (c == 0)" << endl
+                 << "return 0;"
+                 << endl;
+
+            if (custom_alloc)
             {
-              // copy c-tor
-              //
-              os << scope << "::" << type << "::" << endl
-                 << type << " (const " << type << "& x)"
-                 << "{"
-                 << "XSDE_UNUSED (x);";
+              if (exceptions)
+                os << "::xsde::cxx::alloc_guard ag (c);";
 
-              All::contains (a, contains_copy_);
+              os << "new (c) " << type << ";";
 
-              os << "}";
+              if (exceptions)
+                os << "ag.release ();";
+            }
 
-              // operator=
-              //
-              os << scope << "::" << type << "& " << scope << "::" <<
-                type << "::" << endl
-                 << "operator= (const " << type << "& x)"
-                 << "{"
-                 << "XSDE_UNUSED (x);";
+            if (exceptions)
+              os << "::xsde::cxx::guard< " << type << " > g (c);"
+                 << "this->_copy (*c);"
+                 << "g.release ();";
+            else
+            {
+              os << "if (!this->_copy (*c))"
+                 << "{";
 
-              All::contains (a, contains_assign_);
+              if (!custom_alloc)
+                os << "delete c;";
+              else
+                os << "c->~" << type << " ();"
+                   << "::xsde::cxx::free (c);";
 
-              os << "return *this;"
+              os << "return 0;"
                  << "}";
             }
+
+            os << "return c;"
+               << "}";
           }
         }
 
@@ -1462,6 +2202,7 @@ namespace CXX
         Traversal::ContainsParticle& contains_dtor_;
         Traversal::ContainsParticle& contains_copy_;
         Traversal::ContainsParticle& contains_assign_;
+        Traversal::ContainsParticle& contains_clone_;
       };
 
       struct Choice: Traversal::Choice, Context
@@ -1475,12 +2216,14 @@ namespace CXX
               particle_free_ (c, ChoiceParticle::free),
               particle_alloc_ (c, ChoiceParticle::alloc),
               particle_copy_ (c, ChoiceParticle::copy),
-              particle_assign_ (c, ChoiceParticle::assign)
+              particle_assign_ (c, ChoiceParticle::assign),
+              particle_clone_ (c)
         {
           contains_free_ >> particle_free_;
           contains_alloc_ >> particle_alloc_;
           contains_copy_ >> particle_copy_;
           contains_assign_ >> particle_assign_;
+          contains_clone_ >> particle_clone_;
         }
 
         virtual Void
@@ -1499,6 +2242,8 @@ namespace CXX
 
             String const& scope (Context::scope (c));
 
+            Boolean fl (fixed_length (c));
+
             // c-tor ()
             //
             os << scope << "::" << type << "::" << endl
@@ -1517,7 +2262,7 @@ namespace CXX
               arm_tag << " (" << bad_tag << "));"
                << "}";
 
-            if (fixed_length (c))
+            if (fl)
             {
               // copy c-tor
               //
@@ -1586,6 +2331,104 @@ namespace CXX
                << "}";
 
             Choice::contains (c, contains_func_);
+
+            // _clone
+            //
+            if (!fl && clone)
+            {
+              //
+              // _copy
+              //
+              String const& arm (earm (c));
+
+              os << (exceptions ? "void " : "bool ") << scope << "::" <<
+                type << "::" << endl
+                 << "_copy (" << type << "& c) const"
+                 << "{"
+                 << "c." << arm << " (this->" << arm << " ());"
+                 << endl
+                 << "switch (this->" << arm << " ())"
+                 << "{";
+
+              Choice::contains (c, contains_clone_);
+
+              os << "default:" << endl
+                 << "break;"
+                 << "}";
+
+              // Copy custom data.
+              //
+              if (c.context ().count ("cd-name"))
+              {
+                String const& m (ecd_member (c));
+
+                if (exceptions)
+                  os << "this->" << m << ".copy (c." << m << ");";
+                else
+                  os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                     << "return false;"
+                     << endl;
+              }
+
+              if (!exceptions)
+                os << "return true;";
+
+              os << "}";
+
+              //
+              // _clone
+              //
+
+              os << scope << "::" << type << "* " << scope << "::" <<
+                type << "::" << endl
+                 << "_clone () const"
+                 << "{";
+
+              if (!custom_alloc)
+                os << type << "* c = new " << type << ";";
+              else
+                os << type << "* c = static_cast< " << type << "* > (" << endl
+                   << "::xsde::cxx::alloc (sizeof (" << type << ")));";
+
+              if (!exceptions)
+                os << endl
+                   << "if (c == 0)" << endl
+                   << "return 0;"
+                   << endl;
+
+              if (custom_alloc)
+              {
+                if (exceptions)
+                  os << "::xsde::cxx::alloc_guard ag (c);";
+
+                os << "new (c) " << type << ";";
+
+                if (exceptions)
+                  os << "ag.release ();";
+              }
+
+              if (exceptions)
+                os << "::xsde::cxx::guard< " << type << " > g (c);"
+                   << "this->_copy (*c);"
+                   << "g.release ();";
+              else
+              {
+                os << "if (!this->_copy (*c))"
+                   << "{";
+
+                if (!custom_alloc)
+                  os << "delete c;";
+                else
+                  os << "c->~" << type << " ();"
+                     << "::xsde::cxx::free (c);";
+
+                os << "return 0;"
+                   << "}";
+              }
+
+              os << "return c;"
+                 << "}";
+            }
           }
 
           Choice::contains (c);
@@ -1606,6 +2449,9 @@ namespace CXX
 
         ChoiceParticle particle_assign_;
         Traversal::ContainsParticle contains_assign_;
+
+        ParticleInChoiceClone particle_clone_;
+        Traversal::ContainsParticle contains_clone_;
       };
 
 
@@ -1617,6 +2463,7 @@ namespace CXX
                   Traversal::ContainsParticle& contains_dtor,
                   Traversal::ContainsParticle& contains_copy,
                   Traversal::ContainsParticle& contains_assign,
+                  Traversal::ContainsParticle& contains_clone,
                   Traversal::ContainsParticle& contains_func)
             : Context (c),
               in_choice_ (in_choice),
@@ -1624,6 +2471,7 @@ namespace CXX
               contains_dtor_ (contains_dtor),
               contains_copy_ (contains_copy),
               contains_assign_ (contains_assign),
+              contains_clone_ (contains_clone),
               contains_func_ (contains_func)
         {
         }
@@ -1639,6 +2487,8 @@ namespace CXX
             String const& type (etype (s));
             String const& scope (Context::scope (s));
 
+            Boolean fl (fixed_length (s));
+
             // c-tor ()
             //
             os << scope << "::" << type << "::" << endl
@@ -1659,7 +2509,7 @@ namespace CXX
 
             os << "}";
 
-            if (fixed_length (s))
+            if (fl)
             {
               // copy c-tor
               //
@@ -1686,6 +2536,95 @@ namespace CXX
                  << "}";
             }
 
+            // _clone
+            //
+            if (!fl && clone)
+            {
+              //
+              // _copy
+              //
+
+              os << (exceptions ? "void " : "bool ") << scope << "::" <<
+                type << "::" << endl
+                 << "_copy (" << type << "& c) const"
+                 << "{";
+
+              Sequence::contains (s, contains_clone_);
+
+              // Copy custom data.
+              //
+              if (s.context ().count ("cd-name"))
+              {
+                String const& m (ecd_member (s));
+
+                if (exceptions)
+                  os << "this->" << m << ".copy (c." << m << ");";
+                else
+                  os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                     << "return false;"
+                     << endl;
+              }
+
+              if (!exceptions)
+                os << "return true;";
+
+              os << "}";
+
+              //
+              // _clone
+              //
+
+              os << scope << "::" << type << "* " << scope << "::" <<
+                type << "::" << endl
+                 << "_clone () const"
+                 << "{";
+
+              if (!custom_alloc)
+                os << type << "* c = new " << type << ";";
+              else
+                os << type << "* c = static_cast< " << type << "* > (" << endl
+                   << "::xsde::cxx::alloc (sizeof (" << type << ")));";
+
+              if (!exceptions)
+                os << endl
+                   << "if (c == 0)" << endl
+                   << "return 0;"
+                   << endl;
+
+              if (custom_alloc)
+              {
+                if (exceptions)
+                  os << "::xsde::cxx::alloc_guard ag (c);";
+
+                os << "new (c) " << type << ";";
+
+                if (exceptions)
+                  os << "ag.release ();";
+              }
+
+              if (exceptions)
+                os << "::xsde::cxx::guard< " << type << " > g (c);"
+                   << "this->_copy (*c);"
+                   << "g.release ();";
+              else
+              {
+                os << "if (!this->_copy (*c))"
+                   << "{";
+
+                if (!custom_alloc)
+                  os << "delete c;";
+                else
+                  os << "c->~" << type << " ();"
+                     << "::xsde::cxx::free (c);";
+
+                os << "return 0;"
+                   << "}";
+              }
+
+              os << "return c;"
+                 << "}";
+            }
+
             Sequence::contains (s, contains_func_);
           }
 
@@ -1698,10 +2637,11 @@ namespace CXX
         Traversal::ContainsParticle& contains_dtor_;
         Traversal::ContainsParticle& contains_copy_;
         Traversal::ContainsParticle& contains_assign_;
+        Traversal::ContainsParticle& contains_clone_;
         Traversal::ContainsParticle& contains_func_;
       };
 
-      struct Complex : Traversal::Complex, Context
+      struct Complex: Traversal::Complex, Context
       {
         Complex (Context& c)
             : Context (c),
@@ -1747,13 +2687,22 @@ namespace CXX
               choice_in_sequence_assign_ (c),
               sequence_in_sequence_assign_ (c),
 
+              // Clone.
+              //
+              attribute_clone_ (c),
+              element_clone_ (c),
+              all_clone_ (c),
+              choice_in_sequence_clone_ (c),
+              sequence_in_sequence_clone_ (c),
+
               // Nested c-tors, etc.
               //
               all_ (c,
                     all_contains_ctor_,
                     all_contains_dtor_,
                     all_contains_copy_,
-                    all_contains_assign_),
+                    all_contains_assign_,
+                    all_contains_clone_),
               choice_in_choice_ (c, true, choice_contains_func_),
               choice_in_sequence_ (c, false, choice_contains_func_),
               sequence_in_choice_ (
@@ -1763,6 +2712,7 @@ namespace CXX
                 sequence_contains_dtor_,
                 sequence_contains_copy_,
                 sequence_contains_assign_,
+                sequence_contains_clone_,
                 sequence_contains_func_),
               sequence_in_sequence_ (
                 c,
@@ -1771,6 +2721,7 @@ namespace CXX
                 sequence_contains_dtor_,
                 sequence_contains_copy_,
                 sequence_contains_assign_,
+                sequence_contains_clone_,
                 sequence_contains_func_)
         {
           // Functions.
@@ -1850,6 +2801,21 @@ namespace CXX
           contains_compositor_assign_ >> choice_in_sequence_assign_;
           contains_compositor_assign_ >> sequence_in_sequence_assign_;
 
+          // Clone.
+          //
+          attribute_names_clone_ >> attribute_clone_;
+
+          all_clone_ >> all_contains_clone_ >> element_clone_;
+
+          sequence_in_sequence_clone_ >> sequence_contains_clone_;
+          sequence_contains_clone_ >> element_clone_;
+          sequence_contains_clone_ >> choice_in_sequence_clone_;
+          sequence_contains_clone_ >> sequence_in_sequence_clone_;
+
+          contains_compositor_clone_ >> all_clone_;
+          contains_compositor_clone_ >> choice_in_sequence_clone_;
+          contains_compositor_clone_ >> sequence_in_sequence_clone_;
+
           // Nested c-tors, etc.
           //
           all_ >> all_contains_;
@@ -1880,6 +2846,7 @@ namespace CXX
           if (!name)
             return;
 
+          Boolean fl (fixed_length (c));
           Boolean poly (polymorphic (c));
           Boolean restriction (restriction_p (c));
 
@@ -1924,7 +2891,7 @@ namespace CXX
 
           if (!restriction)
           {
-            if (fixed_length (c))
+            if (fl)
             {
               // copy c-tor
               //
@@ -1980,6 +2947,130 @@ namespace CXX
               Complex::contains_compositor (c, contains_compositor_func_);
           }
 
+          // _clone
+          //
+          if (!fl && clone)
+          {
+            //
+            // _copy
+            //
+
+            os << (exceptions ? "void " : "bool ") << name << "::" << endl
+               << "_copy (" << name << "& c) const"
+               << "{"
+               << "XSDE_UNUSED (c);"
+               << endl;
+
+            // Copy the base.
+            //
+            if (c.inherits_p ())
+            {
+              SemanticGraph::Type& b (c.inherits ().base ());
+
+              if (fixed_length (b))
+              {
+                os << "static_cast< ";
+                base_name_.dispatch (b);
+                os << "& > (c) = *this;";
+              }
+              else
+              {
+                os << "const ";
+                base_name_.dispatch (b);
+                os << "& b = *this;";
+
+                if (exceptions)
+                  os << "b._copy (c);";
+                else
+                  os << "if (!b._copy (c))" << endl
+                     << "return false;"
+                     << endl;
+              }
+            }
+
+            // Copy members.
+            //
+            if (!restriction)
+            {
+              Complex::names (c, attribute_names_clone_);
+
+              if (c.contains_compositor_p ())
+                Complex::contains_compositor (c, contains_compositor_clone_);
+            }
+
+            // Copy custom data.
+            //
+            if (c.context ().count ("cd-name"))
+            {
+              String const& m (ecd_member (c));
+
+              if (exceptions)
+                os << "this->" << m << ".copy (c." << m << ");";
+              else
+                os << "if (this->" << m << ".copy (c." << m << "))" << endl
+                   << "return false;"
+                   << endl;
+            }
+
+            if (!exceptions)
+              os << "return true;";
+
+            os << "}";
+
+            //
+            // _clone
+            //
+
+            os << name << "* "  << name << "::" << endl
+               << "_clone () const"
+               << "{";
+
+            if (!custom_alloc)
+              os << name << "* c = new " << name << ";";
+            else
+              os << name << "* c = static_cast< " << name << "* > (" << endl
+                 << "::xsde::cxx::alloc (sizeof (" << name << ")));";
+
+            if (!exceptions)
+              os << endl
+                 << "if (c == 0)" << endl
+                 << "return 0;"
+                 << endl;
+
+            if (custom_alloc)
+            {
+              if (exceptions)
+                os << "::xsde::cxx::alloc_guard ag (c);";
+
+              os << "new (c) " << name << ";";
+
+              if (exceptions)
+                os << "ag.release ();";
+            }
+
+            if (exceptions)
+              os << "::xsde::cxx::guard< " << name << " > g (c);"
+                 << "this->_copy (*c);"
+                 << "g.release ();";
+            else
+            {
+              os << "if (!this->_copy (*c))"
+                 << "{";
+
+              if (!custom_alloc)
+                os << "delete c;";
+              else
+                os << "c->~" << name << " ();"
+                   << "::xsde::cxx::free (c);";
+
+              os << "return 0;"
+                 << "}";
+            }
+
+            os << "return c;"
+               << "}";
+          }
+
           if (poly && typeinfo)
           {
             String id (c.name ());
@@ -2101,6 +3192,20 @@ namespace CXX
 
         Traversal::ContainsCompositor contains_compositor_assign_;
 
+        // Clone.
+        //
+        AttributeClone attribute_clone_;
+        Traversal::Names attribute_names_clone_;
+
+        ElementClone element_clone_;
+        AllClone all_clone_;
+        ChoiceInSequenceClone choice_in_sequence_clone_;
+        SequenceInSequenceClone sequence_in_sequence_clone_;
+        Traversal::ContainsParticle all_contains_clone_;
+        Traversal::ContainsParticle sequence_contains_clone_;
+
+        Traversal::ContainsCompositor contains_compositor_clone_;
+
         // Nested c-tors, etc.
         //
         All all_;
@@ -2129,6 +3234,10 @@ namespace CXX
       ctx.os << "#include <new>" << endl
              << endl;
 
+      if (ctx.clone && ctx.exceptions)
+        ctx.os << "#include <xsde/cxx/guard.hxx>" << endl
+               << endl;
+
       Traversal::Schema schema;
       Traversal::Sources sources;
       Traversal::Names names_ns, names;