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| <h1 align="center"><a href="../index.html">Boost.Python</a></h1> |
| |
| <h2 align="center">Header |
| <boost/python/return_opaque_pointer.hpp></h2> |
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| <h2>Contents</h2> |
| |
| <dl class="page-index"> |
| <dt><a href="#classes">Classes</a></dt> |
| |
| <dd> |
| <dl class="page-index"> |
| <dt><a href="#return_opaque_pointer-spec">Class |
| <code>return_opaque_pointer</code></a></dt> |
| |
| <dd> |
| <dl class="page-index"> |
| <dt><a href="#return_opaque_pointer-spec-synopsis">Class |
| <code>return_opaque_pointer</code> synopsis</a></dt> |
| |
| <dt><a href="#return_opaque_pointer-spec-metafunctions">Class |
| <code>return_opaque_pointer</code> metafunctions</a></dt> |
| </dl> |
| </dd> |
| </dl> |
| </dd> |
| |
| <dt><a href="#examples">Example</a></dt> |
| |
| <dt><a href="#see-also">See Also</a></dt> |
| </dl> |
| <hr> |
| |
| <h2><a name="classes"></a>Classes</h2> |
| |
| <h3><a name="return_opaque_pointer-spec"></a>Class |
| <code>return_opaque_pointer</code></h3> |
| |
| <p><code>return_opaque_pointer</code> is a model of |
| <a href="ResultConverter.html#ResultConverterGenerator-concept"> |
| ResultConverterGenerator</a> |
| which can be used to wrap C++ functions returning pointers to |
| undefined types such that the return value is copied into a |
| new Python object.</p> |
| <p>In addition to specifying the <code>return_opaque_pointer</code> |
| policy the <a href="opaque.html#BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID-spec"> |
| <code>BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID</code></a> macro must be |
| used to define specializations for the |
| <a href="type_id.html#type_id-spec">type_id</a> function |
| on the type pointed to by returned pointer.</p> |
| |
| <h4><a name="return_opaque_pointer-spec-synopsis"></a>Class |
| <code>return_opaque_pointer</code> synopsis</h4> |
| <pre> |
| namespace boost { namespace python |
| { |
| struct return_opaque_pointer |
| { |
| template <class R> struct apply; |
| }; |
| }} |
| </pre> |
| |
| <h4><a name="return_opaque_pointer-spec-metafunctions"></a>Class |
| <code>return_opaque_pointer</code> metafunctions</h4> |
| <pre> |
| template <class R> struct apply |
| </pre> |
| |
| <dl class="metafunction-semantics"> |
| <dt><b>Returns:</b> <code>typedef |
| detail::opaque_conversion_holder<R> |
| type;</code></dt> |
| </dl> |
| |
| <h2><a name="examples"></a>Example</h2> |
| |
| <h3>C++ Module Definition</h3> |
| <pre> |
| # include <boost/python/return_opaque_pointer.hpp> |
| # include <boost/python/def.hpp> |
| # include <boost/python/module.hpp> |
| # include <boost/python/return_value_policy.hpp> |
| |
| typedef struct opaque_ *opaque; |
| |
| opaque the_op = ((opaque) 0x47110815); |
| |
| opaque get () { return the_op; } |
| void use (opaque op) { |
| if (op != the_op) |
| throw std::runtime_error (std::string ("failed")); |
| } |
| |
| void failuse (opaque op) { |
| if (op == the_op) |
| throw std::runtime_error (std::string ("success")); |
| } |
| |
| BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(opaque_) |
| |
| namespace bpl = boost::python; |
| |
| BOOST_PYTHON_MODULE(opaque_ext) |
| { |
| bpl::def ( |
| "get", &::get, bpl::return_value_policy<bpl::return_opaque_pointer>()); |
| bpl::def ("use", &::use); |
| bpl::def ("failuse", &::failuse); |
| } |
| </pre> |
| |
| <h3>Python Code</h3> |
| <pre> |
| """ |
| >>> from opaque_ext import * |
| >>> # |
| >>> # Check for correct conversion |
| >>> use(get()) |
| >>> failuse(get()) |
| Traceback (most recent call last): |
| ... |
| RuntimeError: success |
| >>> # |
| >>> # Check that there is no conversion from integers ... |
| >>> use(0) |
| Traceback (most recent call last): |
| ... |
| TypeError: bad argument type for built-in operation |
| >>> # |
| >>> # ... and from strings to opaque objects |
| >>> use("") |
| Traceback (most recent call last): |
| ... |
| TypeError: bad argument type for built-in operation |
| """ |
| def run(args = None): |
| import sys |
| import doctest |
| |
| if args is not None: |
| sys.argv = args |
| return doctest.testmod(sys.modules.get(__name__)) |
| |
| if __name__ == '__main__': |
| print "running..." |
| import sys |
| sys.exit(run()[0]) |
| </pre> |
| |
| <h2><a name="see-also"></a>See Also</h2> |
| <p> |
| <a href="opaque.html"> |
| opaque</a> |
| </p> |
| |
| <p>Revised |
| 28 January, 2003 |
| </p> |
| |
| <p><i>© Copyright 2003 Haufe Mediengruppe. All Rights |
| Reserved.</i></p> |
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