Added boost header

test/external/boost/python/converter/as_to_python_function.hpp

@@ -0,0 +1,49 @@
+// Copyright David Abrahams 2002.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef AS_TO_PYTHON_FUNCTION_DWA2002121_HPP
+# define AS_TO_PYTHON_FUNCTION_DWA2002121_HPP
+# include <boost/python/converter/to_python_function_type.hpp>
+
+namespace boost { namespace python { namespace converter { 
+
+// Given a typesafe to_python conversion function, produces a
+// to_python_function_t which can be registered in the usual way.
+template <class T, class ToPython>
+struct as_to_python_function
+{
+    // Assertion functions used to prevent wrapping of converters
+    // which take non-const reference parameters. The T* argument in
+    // the first overload ensures it isn't used in case T is a
+    // reference.
+    template <class U>
+    static void convert_function_must_take_value_or_const_reference(U(*)(T), int, T* = 0) {}
+    template <class U>
+    static void convert_function_must_take_value_or_const_reference(U(*)(T const&), long ...) {}
+        
+    static PyObject* convert(void const* x)
+    {
+        convert_function_must_take_value_or_const_reference(&ToPython::convert, 1L);
+        
+        // Yes, the const_cast below opens a hole in const-correctness,
+        // but it's needed to convert auto_ptr<U> to python.
+        //
+        // How big a hole is it?  It allows ToPython::convert() to be
+        // a function which modifies its argument. The upshot is that
+        // client converters applied to const objects may invoke
+        // undefined behavior. The damage, however, is limited by the
+        // use of the assertion function. Thus, the only way this can
+        // modify its argument is if T is an auto_ptr-like type. There
+        // is still a const-correctness hole w.r.t. auto_ptr<U> const,
+        // but c'est la vie.
+        return ToPython::convert(*const_cast<T*>(static_cast<T const*>(x)));
+    }
+#ifndef BOOST_PYTHON_NO_PY_SIGNATURES
+    static PyTypeObject const * get_pytype() { return ToPython::get_pytype(); }
+#endif
+};
+
+}}} // namespace boost::python::converter
+
+#endif // AS_TO_PYTHON_FUNCTION_DWA2002121_HPP