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/python/ssize_t.hpp>
11 # include <boost/implicit_cast.hpp>
12 # include <string>
13 # include <complex>
14 # include <boost/limits.hpp>
15 
16 // Since all we can use to decide how to convert an object to_python
17 // is its C++ type, there can be only one such converter for each
18 // type. Therefore, for built-in conversions we can bypass registry
19 // lookups using explicit specializations of arg_to_python and
20 // result_to_python.
21 
22 namespace boost { namespace python {
23 
24 namespace converter
25 {
26   template <class T> struct arg_to_python;
27   BOOST_PYTHON_DECL PyObject* do_return_to_python(char);
28   BOOST_PYTHON_DECL PyObject* do_return_to_python(char const*);
29   BOOST_PYTHON_DECL PyObject* do_return_to_python(PyObject*);
30   BOOST_PYTHON_DECL PyObject* do_arg_to_python(PyObject*);
31 }
32 
33 // Provide specializations of to_python_value
34 template <class T> struct to_python_value;
35 
36 namespace detail
37 {
38   // Since there's no registry lookup, always report the existence of
39   // a converter.
40   struct builtin_to_python
41   {
42       // This information helps make_getter() decide whether to try to
43       // return an internal reference or not. I don't like it much,
44       // but it will have to serve for now.
45       BOOST_STATIC_CONSTANT(bool, uses_registry = false);
46   };
47 }
48 
49 // Use expr to create the PyObject corresponding to x
50 # define BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(T, expr, pytype)\
51     template <> struct to_python_value<T&>                      \
52         : detail::builtin_to_python                             \
53     {                                                           \
54         inline PyObject* operator()(T const& x) const           \
55         {                                                       \
56             return (expr);                                      \
57         }                                                       \
58         inline PyTypeObject const* get_pytype() const           \
59         {                                                       \
60             return (pytype);                                    \
61         }                                                       \
62     };                                                          \
63     template <> struct to_python_value<T const&>                \
64         : detail::builtin_to_python                             \
65     {                                                           \
66         inline PyObject* operator()(T const& x) const           \
67         {                                                       \
68             return (expr);                                      \
69         }                                                       \
70         inline PyTypeObject const* get_pytype() const           \
71         {                                                       \
72             return (pytype);                                    \
73         }                                                       \
74     };
75 
76 # define BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE(T, expr)   \
77     namespace converter                                 \
78     {                                                   \
79       template <> struct arg_to_python< T >             \
80         : handle<>                                      \
81       {                                                 \
82           arg_to_python(T const& x)                     \
83             : python::handle<>(expr) {}                 \
84       };                                                \
85     }
86 
87 // Specialize argument and return value converters for T using expr
88 # define BOOST_PYTHON_TO_PYTHON_BY_VALUE(T, expr, pytype)  \
89         BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(T,expr, pytype)  \
90         BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE(T,expr)
91 
92 // Specialize converters for signed and unsigned T to Python Int
93 #if PY_VERSION_HEX >= 0x03000000
94 
95 # define BOOST_PYTHON_TO_INT(T)                                         \
96     BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed T, ::PyLong_FromLong(x), &PyLong_Type)      \
97     BOOST_PYTHON_TO_PYTHON_BY_VALUE(unsigned T, ::PyLong_FromUnsignedLong(x), &PyLong_Type)
98 
99 #else
100 
101 # define BOOST_PYTHON_TO_INT(T)                                         \
102     BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed T, ::PyInt_FromLong(x), &PyInt_Type)      \
103     BOOST_PYTHON_TO_PYTHON_BY_VALUE(                                    \
104         unsigned T                                                      \
105         , static_cast<unsigned long>(x) > static_cast<unsigned long>(   \
106                 (std::numeric_limits<long>::max)())                     \
107         ? ::PyLong_FromUnsignedLong(x)                                  \
108         : ::PyInt_FromLong(x), &PyInt_Type)
109 #endif
110 
111 // Bool is not signed.
112 #if PY_VERSION_HEX >= 0x02030000
113 BOOST_PYTHON_TO_PYTHON_BY_VALUE(bool, ::PyBool_FromLong(x), &PyBool_Type)
114 #else
115 BOOST_PYTHON_TO_PYTHON_BY_VALUE(bool, ::PyInt_FromLong(x), &PyInt_Type)
116 #endif
117 
118 // note: handles signed char and unsigned char, but not char (see below)
119 BOOST_PYTHON_TO_INT(char)
120 
121 BOOST_PYTHON_TO_INT(short)
122 BOOST_PYTHON_TO_INT(int)
123 BOOST_PYTHON_TO_INT(long)
124 
125 # if defined(_MSC_VER) && defined(_WIN64) && PY_VERSION_HEX < 0x03000000
126 /* Under 64-bit Windows std::size_t is "unsigned long long". To avoid
127    getting a Python long for each std::size_t the value is checked before
128    the conversion. A std::size_t is converted to a simple Python int
129    if possible; a Python long appears only if the value is too small or
130    too large to fit into a simple int. */
131 BOOST_PYTHON_TO_PYTHON_BY_VALUE(
132     signed BOOST_PYTHON_LONG_LONG,
133     (   x < static_cast<signed BOOST_PYTHON_LONG_LONG>(
134             (std::numeric_limits<long>::min)())
135      || x > static_cast<signed BOOST_PYTHON_LONG_LONG>(
136             (std::numeric_limits<long>::max)()))
137     ? ::PyLong_FromLongLong(x)
138     : ::PyInt_FromLong(static_cast<long>(x)), &PyInt_Type)
139 BOOST_PYTHON_TO_PYTHON_BY_VALUE(
140     unsigned BOOST_PYTHON_LONG_LONG,
141     x > static_cast<unsigned BOOST_PYTHON_LONG_LONG>(
142       (std::numeric_limits<long>::max)())
143     ? ::PyLong_FromUnsignedLongLong(x)
144     : ::PyInt_FromLong(static_cast<long>(x)), &PyInt_Type)
145 //
146 # elif defined(HAVE_LONG_LONG) // using Python's macro instead of Boost's
147                                // - we don't seem to get the config right
148                                // all the time.
149 BOOST_PYTHON_TO_PYTHON_BY_VALUE(signed BOOST_PYTHON_LONG_LONG, ::PyLong_FromLongLong(x), &PyLong_Type)
150 BOOST_PYTHON_TO_PYTHON_BY_VALUE(unsigned BOOST_PYTHON_LONG_LONG, ::PyLong_FromUnsignedLongLong(x), &PyLong_Type)
151 # endif
152 
153 # undef BOOST_TO_PYTHON_INT
154 
155 #if PY_VERSION_HEX >= 0x03000000
156 BOOST_PYTHON_TO_PYTHON_BY_VALUE(char, converter::do_return_to_python(x), &PyUnicode_Type)
157 BOOST_PYTHON_TO_PYTHON_BY_VALUE(char const*, converter::do_return_to_python(x), &PyUnicode_Type)
158 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::string, ::PyUnicode_FromStringAndSize(x.data(),implicit_cast<ssize_t>(x.size())), &PyUnicode_Type)
159 #else
160 BOOST_PYTHON_TO_PYTHON_BY_VALUE(char, converter::do_return_to_python(x), &PyString_Type)
161 BOOST_PYTHON_TO_PYTHON_BY_VALUE(char const*, converter::do_return_to_python(x), &PyString_Type)
162 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::string, ::PyString_FromStringAndSize(x.data(),implicit_cast<ssize_t>(x.size())), &PyString_Type)
163 #endif
164 
165 #if defined(Py_USING_UNICODE) && !defined(BOOST_NO_STD_WSTRING)
166 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::wstring, ::PyUnicode_FromWideChar(x.data(),implicit_cast<ssize_t>(x.size())), &PyUnicode_Type)
167 # endif
168 BOOST_PYTHON_TO_PYTHON_BY_VALUE(float, ::PyFloat_FromDouble(x), &PyFloat_Type)
169 BOOST_PYTHON_TO_PYTHON_BY_VALUE(double, ::PyFloat_FromDouble(x), &PyFloat_Type)
170 BOOST_PYTHON_TO_PYTHON_BY_VALUE(long double, ::PyFloat_FromDouble(x), &PyFloat_Type)
171 BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE(PyObject*, converter::do_return_to_python(x), 0)
172 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<float>, ::PyComplex_FromDoubles(x.real(), x.imag()), &PyComplex_Type)
173 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<double>, ::PyComplex_FromDoubles(x.real(), x.imag()), &PyComplex_Type)
174 BOOST_PYTHON_TO_PYTHON_BY_VALUE(std::complex<long double>, ::PyComplex_FromDoubles(x.real(), x.imag()), &PyComplex_Type)
175 
176 # undef BOOST_PYTHON_RETURN_TO_PYTHON_BY_VALUE
177 # undef BOOST_PYTHON_ARG_TO_PYTHON_BY_VALUE
178 # undef BOOST_PYTHON_TO_PYTHON_BY_VALUE
179 # undef BOOST_PYTHON_TO_INT
180 
181 namespace converter
182 {
183 
184   void initialize_builtin_converters();
185 
186 }
187 
188 }} // namespace boost::python::converter
189 
190 #endif // BUILTIN_CONVERTERS_DWA2002124_HPP
191