[575] | 1 | /* -*- mode:c++ -*- */ |
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| 2 | |
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| 3 | /** @file |
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| 4 | |
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| 5 | Boost.Python conversion functions from STL containers to Python |
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| 6 | sequences and vice versa. |
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| 7 | |
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| 8 | $Id: pyconversions.h 575 2005-04-07 02:11:59Z mar637 $ |
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| 9 | |
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| 10 | */ |
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| 11 | |
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| 12 | #ifndef PY_CONVERSIONS_H |
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| 13 | #define PY_CONVERSIONS_H |
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| 14 | |
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| 15 | #include <vector> |
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| 16 | |
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| 17 | #include <boost/python.hpp> |
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| 18 | |
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| 19 | using namespace boost::python; |
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| 20 | |
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| 21 | /** A wrapper of a conversion function to convert a STL vector to a |
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| 22 | Python tuple. This class satisfies the requirements of the |
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| 23 | boost::python::to_python_converter conversion template argument. |
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| 24 | |
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| 25 | Copied from |
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| 26 | scitbx/include/scitbx/boost_python/container_conversions.h that is |
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| 27 | described in the <a |
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| 28 | href="http://www.boost.org/libs/python/doc/v2/faq.html"> |
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| 29 | Boost.Python FAQ. </a> |
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| 30 | |
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| 31 | @author Ralf W. Grosse-Kunstleve <rwgk@yahoo.com> of |
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| 32 | <a href="http://www.lbl.gov/">Lawrence Berkeley National Laboratory</a> |
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| 33 | */ |
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| 34 | template < typename ContainerType > |
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| 35 | struct to_tuple |
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| 36 | { |
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| 37 | /** Creates and returns a Python @c tuple from the elements copied |
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| 38 | from a STL container. The @c ContainerType must be a vector, |
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| 39 | but may contain any type of object supported by the |
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| 40 | boost::python::object constructor. */ |
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| 41 | static PyObject* convert (ContainerType const& c) |
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| 42 | { |
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| 43 | using boost::python::incref; // works around gcc 2.96 bug |
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| 44 | using boost::python::list; // dito |
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| 45 | list result; |
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| 46 | typename ContainerType::const_iterator i = c.begin(); |
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| 47 | for( ; i != c.end(); ++i) |
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| 48 | { |
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| 49 | result.append(*i); |
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| 50 | } |
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| 51 | return incref(tuple(result).ptr()); |
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| 52 | } |
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| 53 | }; |
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| 54 | |
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| 55 | /** Converts an STL vector of T objects to Python tuple. |
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| 56 | |
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| 57 | Copied from |
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| 58 | scitbx/include/scitbx/boost_python/container_conversions.h that is |
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| 59 | described in the <a |
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| 60 | href="http://www.boost.org/libs/python/doc/v2/faq.html"> |
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| 61 | Boost.Python FAQ. </a> |
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| 62 | |
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| 63 | @author Ralf W. Grosse-Kunstleve <rwgk@yahoo.com> of |
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| 64 | <a href="http://www.lbl.gov/">Lawrence Berkeley National Laboratory</a> |
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| 65 | */ |
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| 66 | template < typename T > |
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| 67 | struct std_vector_to_tuple |
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| 68 | { |
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| 69 | std_vector_to_tuple () |
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| 70 | { |
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| 71 | to_python_converter < std::vector < T >, |
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| 72 | to_tuple < std::vector < T > > > (); |
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| 73 | } |
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| 74 | }; |
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| 75 | |
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| 76 | // /** Interface to AxesType enumeration. */ |
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| 77 | // struct AxesOwner |
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| 78 | // { |
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| 79 | // public: |
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| 80 | // AxesOwner(){}; |
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| 81 | // typedef AxesType enum_type; |
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| 82 | // }; |
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| 83 | |
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| 84 | // /** Conversion of AxesType enumeration. */ |
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| 85 | // struct EnumTypeConverters |
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| 86 | // : python::enum_as_int_converters <AxesOwner::enum_type> |
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| 87 | // { |
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| 88 | // }; |
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| 89 | |
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| 90 | /** Default operations on all containers for conversion from Python |
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| 91 | container to C++ one. |
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| 92 | |
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| 93 | Copied from |
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| 94 | scitbx/include/scitbx/boost_python/container_conversions.h that is |
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| 95 | described in the <a |
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| 96 | href="http://www.boost.org/libs/python/doc/v2/faq.html"> |
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| 97 | Boost.Python FAQ. </a> |
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| 98 | |
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| 99 | @author Ralf W. Grosse-Kunstleve <rwgk@yahoo.com> of |
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| 100 | <a href="http://www.lbl.gov/">Lawrence Berkeley National Laboratory</a> |
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| 101 | */ |
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| 102 | struct default_policy |
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| 103 | { |
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| 104 | static bool check_convertibility_per_element() { return false; } |
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| 105 | |
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| 106 | template <typename ContainerType> |
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| 107 | static bool check_size(boost::type<ContainerType>, std::size_t sz) |
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| 108 | { |
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| 109 | return true; |
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| 110 | } |
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| 111 | |
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| 112 | template <typename ContainerType> |
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| 113 | static void assert_size(boost::type<ContainerType>, std::size_t sz) {} |
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| 114 | |
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| 115 | template <typename ContainerType> |
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| 116 | static void reserve(ContainerType& a, std::size_t sz) {} |
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| 117 | }; |
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| 118 | |
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| 119 | /** Operations on containers that have variable capacity for |
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| 120 | conversion from Python container to C++ one. |
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| 121 | |
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| 122 | Copied from |
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| 123 | scitbx/include/scitbx/boost_python/container_conversions.h that is |
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| 124 | described in the <a |
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| 125 | href="http://www.boost.org/libs/python/doc/v2/faq.html"> |
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| 126 | Boost.Python FAQ. </a> |
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| 127 | |
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| 128 | @author Ralf W. Grosse-Kunstleve <rwgk@yahoo.com> of |
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| 129 | <a href="http://www.lbl.gov/">Lawrence Berkeley National Laboratory</a> |
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| 130 | */ |
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| 131 | struct variable_capacity_policy : default_policy |
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| 132 | { |
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| 133 | template <typename ContainerType> |
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| 134 | static void reserve(ContainerType& a, std::size_t sz) |
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| 135 | { |
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| 136 | a.reserve(sz); |
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| 137 | } |
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| 138 | |
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| 139 | template <typename ContainerType, typename ValueType> |
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| 140 | static void set_value(ContainerType& a, std::size_t i, ValueType const& v) |
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| 141 | { |
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| 142 | assert(a.size() == i); |
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| 143 | a.push_back(v); |
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| 144 | } |
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| 145 | }; |
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| 146 | |
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| 147 | /** Conversion of Python sequence to C++ container. |
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| 148 | |
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| 149 | Copied from |
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| 150 | scitbx/include/scitbx/boost_python/container_conversions.h that is |
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| 151 | described in the <a |
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| 152 | href="http://www.boost.org/libs/python/doc/v2/faq.html"> |
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| 153 | Boost.Python FAQ. </a> |
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| 154 | |
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| 155 | @author Ralf W. Grosse-Kunstleve <rwgk@yahoo.com> of |
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| 156 | <a href="http://www.lbl.gov/">Lawrence Berkeley National Laboratory</a> |
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| 157 | */ |
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| 158 | template <typename ContainerType, typename ConversionPolicy> |
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| 159 | struct from_python_sequence |
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| 160 | { |
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| 161 | typedef typename ContainerType::value_type container_element_type; |
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| 162 | |
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| 163 | from_python_sequence() |
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| 164 | { |
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| 165 | boost::python::converter::registry::push_back( |
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| 166 | &convertible, |
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| 167 | &construct, |
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| 168 | boost::python::type_id<ContainerType>()); |
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| 169 | } |
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| 170 | |
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| 171 | /** Appears to return @a obj_ptr if it is type of Python sequence |
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| 172 | that can be convertible to C++ container. */ |
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| 173 | static void* convertible(PyObject* obj_ptr) |
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| 174 | { |
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| 175 | using namespace boost::python; |
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| 176 | using boost::python::allow_null; // works around gcc 2.96 bug |
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| 177 | { |
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| 178 | // Restriction to list, tuple, iter, xrange until |
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| 179 | // Boost.Python overload resolution is enhanced. |
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| 180 | // |
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| 181 | // add PySequence_Check() for numarray. |
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| 182 | // |
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| 183 | if (!( PyList_Check(obj_ptr) |
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| 184 | || PyTuple_Check(obj_ptr) |
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| 185 | || PyIter_Check(obj_ptr) |
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| 186 | || PyRange_Check(obj_ptr) |
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| 187 | || PySequence_Check(obj_ptr) )) return 0; |
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| 188 | } |
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| 189 | handle<> obj_iter(allow_null(PyObject_GetIter(obj_ptr))); |
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| 190 | if (!obj_iter.get()) { // must be convertible to an iterator |
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| 191 | PyErr_Clear(); |
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| 192 | return 0; |
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| 193 | } |
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| 194 | if (ConversionPolicy::check_convertibility_per_element()) { |
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| 195 | int obj_size = PyObject_Length(obj_ptr); |
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| 196 | if (obj_size < 0) { // must be a measurable sequence |
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| 197 | PyErr_Clear(); |
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| 198 | return 0; |
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| 199 | } |
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| 200 | if (!ConversionPolicy::check_size( |
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| 201 | boost::type<ContainerType>(), obj_size)) return 0; |
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| 202 | bool is_range = PyRange_Check(obj_ptr); |
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| 203 | //std::size_t i=0; |
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| 204 | int i = 0; |
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| 205 | #ifndef _MSC_VER // because it causes c1001: internal compiler error |
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| 206 | for(;;i++) { |
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| 207 | handle<> py_elem_hdl(allow_null(PyIter_Next(obj_iter.get()))); |
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| 208 | if (PyErr_Occurred()) { |
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| 209 | PyErr_Clear(); |
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| 210 | return 0; |
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| 211 | } |
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| 212 | if (!py_elem_hdl.get()) break; // end of iteration |
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| 213 | object py_elem_obj(py_elem_hdl); |
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| 214 | extract<container_element_type> elem_proxy(py_elem_obj); |
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| 215 | if (!elem_proxy.check()) return 0; |
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| 216 | if (is_range) break; // in a range all elements are of the same type |
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| 217 | } |
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| 218 | if (!is_range) assert(i == obj_size ); |
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| 219 | #endif |
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| 220 | } |
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| 221 | return obj_ptr; |
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| 222 | } |
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| 223 | |
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| 224 | /** Constructs a C++ container from a Python sequence. */ |
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| 225 | static void construct( |
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| 226 | PyObject* obj_ptr, |
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| 227 | boost::python::converter::rvalue_from_python_stage1_data* data) |
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| 228 | { |
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| 229 | using namespace boost::python; |
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| 230 | using boost::python::allow_null; // works around gcc 2.96 bug |
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| 231 | using boost::python::converter::rvalue_from_python_storage; // dito |
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| 232 | using boost::python::throw_error_already_set; // dito |
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| 233 | handle<> obj_iter(PyObject_GetIter(obj_ptr)); |
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| 234 | void* storage = ( |
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| 235 | (rvalue_from_python_storage<ContainerType>*) |
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| 236 | data)->storage.bytes; |
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| 237 | new (storage) ContainerType(); |
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| 238 | data->convertible = storage; |
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| 239 | ContainerType& result = *((ContainerType*)storage); |
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| 240 | std::size_t i=0; |
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| 241 | for(;;i++) { |
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| 242 | handle<> py_elem_hdl(allow_null(PyIter_Next(obj_iter.get()))); |
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| 243 | if (PyErr_Occurred()) throw_error_already_set(); |
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| 244 | if (!py_elem_hdl.get()) break; // end of iteration |
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| 245 | object py_elem_obj(py_elem_hdl); |
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| 246 | extract<container_element_type> elem_proxy(py_elem_obj); |
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| 247 | ConversionPolicy::set_value(result, i, elem_proxy()); |
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| 248 | } |
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| 249 | ConversionPolicy::assert_size(boost::type<ContainerType>(), i); |
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| 250 | } |
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| 251 | |
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| 252 | }; |
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| 253 | |
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| 254 | #endif // PY_CONVERSIONS_H |
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