You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
49 lines
2.1 KiB
49 lines
2.1 KiB
// 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
|
|
|