diff --git a/include/boost/python/detail/base_object.hpp b/include/boost/python/detail/base_object.hpp
index 95a2805c..cf6bb528 100644
--- a/include/boost/python/detail/base_object.hpp
+++ b/include/boost/python/detail/base_object.hpp
@@ -21,10 +21,10 @@ namespace boost { namespace python { namespace detail {
 
 // base_object - adds a constructor and non-virtual destructor to a
 // base Python type (e.g. PyObject, PyTypeObject).
-template <class python_type>
-struct base_object : python_type
+template <class PythonType>
+struct base_object : PythonType
 {
-    typedef python_type base_python_type;
+    typedef PythonType base_python_type;
 
     // Initializes type and reference count. All other fields of base_python_type are 0
     base_object(PyTypeObject* type_obj);
@@ -41,8 +41,8 @@ typedef base_object<PyTypeObject> python_type;
 //
 // base_object member function implementations 
 //
-template <class python_type>
-base_object<python_type>::base_object(PyTypeObject* type_obj)
+template <class PythonType>
+base_object<PythonType>::base_object(PyTypeObject* type_obj)
 {
     base_python_type* bp = this;
 #if !defined(_MSC_VER) || defined(__STLPORT)
@@ -53,8 +53,8 @@ base_object<python_type>::base_object(PyTypeObject* type_obj)
     PyObject_INIT(bp, type_obj);
 }
 
-template <class python_type>
-inline base_object<python_type>::~base_object()
+template <class PythonType>
+inline base_object<PythonType>::~base_object()
 {
     Py_DECREF(ob_type);
 }
diff --git a/include/boost/python/detail/cast.hpp b/include/boost/python/detail/cast.hpp
index e047c0b3..67fe7b34 100644
--- a/include/boost/python/detail/cast.hpp
+++ b/include/boost/python/detail/cast.hpp
@@ -15,14 +15,6 @@
 namespace boost { namespace python {
 
 namespace detail {
-  // The default way of converting a PyObject* or PyTypeObject* to a T*
-  template <class T>
-  struct downcast_traits
-  {
-      template <class U>
-      static T* cast(U* p) { return static_cast<T*>(p); }
-  };
-
   inline PyTypeObject* as_base_object(const PyTypeObject*, PyObject* p)
   {
       return reinterpret_cast<PyTypeObject*>(p);
@@ -54,19 +46,19 @@ template <class T>
 struct downcast
 {
     downcast(PyObject* p)
-        : m_p(detail::downcast_traits<T>::cast(detail::as_base_object((T*)0, p)))
+        : m_p(static_cast<T*>(detail::as_base_object((T*)0, p)))
         {}
     
     downcast(const PyObject* p)
-        : m_p(detail::downcast_traits<T>::cast(detail::as_base_object((const T*)0, p)))
+        : m_p(static_cast<T*>(detail::as_base_object((const T*)0, p)))
         {}
     
     downcast(PyTypeObject* p)
-        : m_p(detail::downcast_traits<T>::cast(p))
+        : m_p(static_cast<T*>(p))
         {}
     
     downcast(const PyTypeObject* p)
-        : m_p(detail::downcast_traits<T>::cast(p))
+        : m_p(static_cast<T*>(p))
         {}
     
     operator T*() const { return m_p; }
diff --git a/include/boost/python/detail/functions.hpp b/include/boost/python/detail/functions.hpp
index 055255e7..16b8e16d 100644
--- a/include/boost/python/detail/functions.hpp
+++ b/include/boost/python/detail/functions.hpp
@@ -46,7 +46,7 @@ class function : public python_object
  private:
     struct type_object;
  private:
-    reference<function> m_overloads;
+    reference<function> m_overloads; // A linked list of the function overloads
 };
 
 // wrapped_function_pointer<> --
@@ -66,7 +66,12 @@ struct wrapped_function_pointer : function
 
  private:
 	PyObject* do_call(PyObject* args, PyObject* keywords) const
-        { return caller<R>::call(m_pf, args, keywords); }
+        {
+            // This is where the boundary between the uniform Python function
+            // interface and the statically-checked C++ function interface is
+            // crossed.
+            return caller<R>::call(m_pf, args, keywords);
+        }
     
     const char* description() const
         { return typeid(F).name(); }
diff --git a/src/functions.cpp b/src/functions.cpp
index 71b59136..a04e2e51 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -61,6 +61,8 @@ function::function()
 
 PyObject* function::call(PyObject* args, PyObject* keywords) const
 {
+    // Traverse the linked list of function overloads until we find one that
+    // matches.
     for (const function* f = this; f != 0; f = f->m_overloads.get())
     {
         PyErr_Clear();
@@ -75,9 +77,14 @@ PyObject* function::call(PyObject* args, PyObject* keywords) const
         }
     }
 
+    // If we get here, no overloads matched the arguments
+
+    // Allow the single-function error-reporting to take effect unless there was
+    // an overload
     if (m_overloads.get() == 0)
         return 0;
 
+    // Synthesize a more-explicit error message
     PyErr_Clear();
     string message("No overloaded functions match (");
     tuple arguments(ref(args, ref::increment_count));
diff --git a/src/types.cpp b/src/types.cpp
index f8cf1ea6..add0ebf0 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -24,6 +24,11 @@ namespace {
 
   using detail::type_object_base;
 
+  // Define a family of forwarding functions that can be calle from a
+  // PyTypeObject's slots. These functions dispatch through a (virtual) member
+  // function pointer in the type_object_base, and handle exceptions in a
+  // uniform way, preventing us from having to rewrite the dispatching code over
+  // and over.
   PyObject* call(PyObject* obj, PyObject* (type_object_base::*f)(PyObject*) const)
   {
       try
@@ -154,6 +159,10 @@ namespace {
 
 extern "C" {
 
+//
+// These functions actually go into the type object's slots, and dispatch to the
+// "call" wrappers defined above.
+//
 static PyObject* do_instance_repr(PyObject* obj)
 {
     return call(obj, &type_object_base::instance_repr);