source: NonGTP/Boost/boost/python/converter/builtin_converters.hpp @ 857

Revision 857, 6.2 KB checked in by igarcia, 19 years ago (diff)
Line 
1// Copyright David Abrahams 2002.
2// Distributed under the Boost Software License, Version 1.0. (See
3// accompanying file LICENSE_1_0.txt or copy at
4// http://www.boost.org/LICENSE_1_0.txt)
5#ifndef BUILTIN_CONVERTERS_DWA2002124_HPP
6# define BUILTIN_CONVERTERS_DWA2002124_HPP
7# include <boost/python/detail/prefix.hpp>
8# include <boost/python/detail/none.hpp>
9# include <boost/python/handle.hpp>
10# include <boost/implicit_cast.hpp>
11# include <string>
12# include <complex>
13# include <boost/limits.hpp>
14
15// Since all we can use to decide how to convert an object to_python
16// is its C++ type, there can be only one such converter for each
17// type. Therefore, for built-in conversions we can bypass registry
18// lookups using explicit specializations of arg_to_python and
19// result_to_python.
20
21namespace boost { namespace python {
22
23namespace converter
24{
25  template <class T> struct arg_to_python;
26  BOOST_PYTHON_DECL PyObject* do_return_to_python(char);
27  BOOST_PYTHON_DECL PyObject* do_return_to_python(char const*);
28  BOOST_PYTHON_DECL PyObject* do_return_to_python(PyObject*);
29  BOOST_PYTHON_DECL PyObject* do_arg_to_python(PyObject*);
30}
31
32// Provide specializations of to_python_value
33template <class T> struct to_python_value;
34
35namespace detail
36{
37  // Since there's no registry lookup, always report the existence of
38  // a converter.
39  struct builtin_to_python
40  {
41      // This information helps make_getter() decide whether to try to
42      // return an internal reference or not. I don't like it much,
43      // but it will have to serve for now.
44      BOOST_STATIC_CONSTANT(bool, uses_registry = false);
45  };
46}
47
48// Use expr to create the PyObject corresponding to x
49# define BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(T, expr)        \
50    template <> struct to_python_value<T&>                      \
51        : detail::builtin_to_python                             \
52    {                                                           \
53        inline PyObject* operator()(T const& x) const           \
54        {                                                       \
55            return (expr);                                      \
56        }                                                       \
57    };                                                          \
58    template <> struct to_python_value<T const&>                \
59        : detail::builtin_to_python                             \
60    {                                                           \
61        inline PyObject* operator()(T const& x) const           \
62        {                                                       \
63            return (expr);                                      \
64        }                                                       \
65    };
66
67# define BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE(T, expr)   \
68    namespace converter                                 \
69    {                                                   \
70      template <> struct arg_to_python< T >             \
71        : handle<>                                      \
72      {                                                 \
73          arg_to_python(T const& x)                     \
74            : python::handle<>(expr) {}                 \
75      };                                                \
76    }
77
78// Specialize argument and return value converters for T using expr
79# define BOOST_PYTHON_TO_PYTHON_BY_VALUE(T, expr)       \
80        BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(T,expr)  \
81        BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE(T,expr)
82
83// Specialize converters for signed and unsigned T to Python Int
84# define BOOST_PYTHON_TO_INT(T)                                         \
85    BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed T, ::PyInt_FromLong(x))      \
86    BOOST_PYTHON_TO_PYTHON_BY_VALUE(                                    \
87        unsigned T                                                      \
88        , static_cast<unsigned long>(x) > static_cast<unsigned long>(   \
89                (std::numeric_limits<long>::max)())                     \
90        ? ::PyLong_FromUnsignedLong(x)                                  \
91        : ::PyInt_FromLong(x))
92
93// Bool is not signed.
94#if PY_VERSION_HEX >= 0x02030000
95BOOST_PYTHON_TO_PYTHON_BY_VALUE(bool, ::PyBool_FromLong(x))
96#else
97BOOST_PYTHON_TO_PYTHON_BY_VALUE(bool, ::PyInt_FromLong(x))
98#endif
99 
100// note: handles signed char and unsigned char, but not char (see below)
101BOOST_PYTHON_TO_INT(char)
102
103BOOST_PYTHON_TO_INT(short)
104BOOST_PYTHON_TO_INT(int)
105BOOST_PYTHON_TO_INT(long)
106
107// using Python's macro instead of Boost's - we don't seem to get the
108// config right all the time.
109# ifdef HAVE_LONG_LONG
110BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed BOOST_PYTHON_LONG_LONG, ::PyLong_FromLongLong(x))
111BOOST_PYTHON_TO_PYTHON_BY_VALUE(unsigned BOOST_PYTHON_LONG_LONG, ::PyLong_FromUnsignedLongLong(x))
112# endif
113   
114# undef BOOST_TO_PYTHON_INT
115
116BOOST_PYTHON_TO_PYTHON_BY_VALUE(char, converter::do_return_to_python(x))
117BOOST_PYTHON_TO_PYTHON_BY_VALUE(char const*, converter::do_return_to_python(x))
118BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::string, ::PyString_FromStringAndSize(x.data(),implicit_cast<int>(x.size())))
119# ifndef BOOST_NO_STD_WSTRING
120BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::wstring, ::PyUnicode_FromWideChar(x.data(),implicit_cast<int>(x.size())))
121# endif
122BOOST_PYTHON_TO_PYTHON_BY_VALUE(float, ::PyFloat_FromDouble(x))
123BOOST_PYTHON_TO_PYTHON_BY_VALUE(double, ::PyFloat_FromDouble(x))
124BOOST_PYTHON_TO_PYTHON_BY_VALUE(long double, ::PyFloat_FromDouble(x))
125BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(PyObject*, converter::do_return_to_python(x))
126BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<float>, ::PyComplex_FromDoubles(x.real(), x.imag()))
127BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<double>, ::PyComplex_FromDoubles(x.real(), x.imag()))
128BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<long double>, ::PyComplex_FromDoubles(x.real(), x.imag()))
129
130# undef BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE
131# undef BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE
132# undef BOOST_PYTHON_TO_PYTHON_BY_VALUE
133# undef BOOST_PYTHON_TO_INT
134   
135namespace converter
136{
137
138  void initialize_builtin_converters();
139
140}
141
142}} // namespace boost::python::converter
143
144#endif // BUILTIN_CONVERTERS_DWA2002124_HPP
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