initial development of NumericDispatcher

[SVN r8022]

numeric.h

@@ -0,0 +1,67 @@
+#ifndef PYCPP_NUMERIC_H
+#define PYCPP_NUMERIC_H
+
+#include <map>
+#include <utility>
+#include "py.h"
+#include "extclass.h"
+
+namespace py {
+
+template <class T, class U>
+struct NumericOperators
+{
+    static PyObject * add(PyObject * l, PyObject * r) 
+    { 
+        return to_python(from_python(l, py::Type<T const &>()) +
+                         from_python(r, py::Type<U const &>())); 
+    }
+    static PyObject * subtract(PyObject * l, PyObject * r) 
+    { 
+        return to_python(from_python(l, py::Type<T const &>()) -
+                         from_python(r, py::Type<U const &>())); 
+    }
+};
+
+typedef std::pair<PyTypeObject *, PyTypeObject *> TypePair;
+
+bool operator<(TypePair const & l, TypePair const & r);
+
+struct NumericDispatcher
+: public PyObject
+{
+    typedef PyObject * (*NumericFunction)(PyObject *, PyObject *);
+    typedef std::map<TypePair, NumericFunction> FunctionRepository;
+    
+    static FunctionRepository add_functions;
+    static FunctionRepository sub_functions;
+    
+    static PyTypeObject type_object;
+    static PyNumberMethods number_methods;
+
+    friend class Module;
+    
+    // store this function in NumericDispatcher's 'nb_add' slot
+    static PyObject * add(PyObject * l, PyObject * r);
+    static PyObject * sub(PyObject * l, PyObject * r);
+    
+    static void coerce(PyObject * & l, PyObject * & r);
+
+    static void init_type_object();
+    static void free_type_object();
+    
+    NumericDispatcher(PyObject * o);
+    static void dealloc(PyObject *self);
+    
+    PyObject * object;
+};
+
+py::Tuple coerce_wrapped(PyObject * l, PyObject * r);
+
+}
+
+inline PyObject * to_python(py::NumericDispatcher * n) { return n; }
+
+
+
+#endif /* PYCPP_NUMERIC_H */