Mojo C++ bindings: more consistent Clone() and Equals().

mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl

Index: mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
index c5c5e815c0aef6788b87963c949c155f144a4018..96b1d25f7af3b91ffca10be7057c877338e88e08 100644
--- a/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
+++ b/mojo/public/tools/bindings/generators/cpp_templates/wrapper_class_declaration.tmpl
@@ -34,37 +34,18 @@ class {{struct.name}} {
   ~{{struct.name}}();
 
   // Clone() is a template so it is only instantiated if it is used. Thus, the
-  // bindings generator does not need to know whether typemapped native types
-  // support operator=.
+  // bindings generator does not need to know whether Clone() or copy
+  // constructor/assignment are available for members.
   template <typename StructPtrType = {{struct.name}}Ptr>
-  {{struct.name}}Ptr Clone() const {
-    // Use StructPtrType to prevent the compiler from trying to compile this
-    // without being asked.
-    StructPtrType rv(New());
-{%-   for field in struct.fields %}
-{%-     if field.kind|is_object_kind and not field.kind|is_string_kind and
-            not field.kind|is_typemapped_kind %}
-    rv->{{field.name}} = {{field.name}}.Clone();
-{%-     else %}
-    rv->{{field.name}} = {{field.name}};
-{%-     endif %}
-{%-   endfor %}
-    return rv;
-  }
+  {{struct.name}}Ptr Clone() const;
 
   // Equals() is a template so it is only instantiated if it is used. Thus, the
-  // bindings generator does not need to know whether typemapped native types
-  // support operator==.
+  // bindings generator does not need to know whether Equals() or == operator
+  // are available for members.
   template <typename T,
             typename std::enable_if<std::is_same<
                 T, {{struct.name}}>::value>::type* = nullptr>
-  bool Equals(const T& other) const {
-  {%-  for field in struct.fields %}
-    if (!mojo::internal::ValueTraits<{{field.kind|cpp_wrapper_type}}>::Equals(this->{{field.name}}, other.{{field.name}}))
-      return false;
-  {%-  endfor %}
-    return true;
-  }
+  bool Equals(const T& other) const;
 
 {#--- Struct members #}
 {%  for field in struct.fields %}