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POboost::python: Python list to std::vector
 

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  1. POboost::python: Python list to std::vector
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    <p>Finally I'm able to use std::vector in python using the [] operator. The trick is to simple provide a container in the boost C++ wrapper which handles the internal vector stuff:</p> <pre><code>#include &lt;boost/python.hpp&gt; #include &lt;vector&gt; class world { std::vector&lt;double&gt; myvec; void add(double n) { this-&gt;myvec.push_back(n); } std::vector&lt;double&gt; show() { return this-&gt;myvec; } }; BOOST_PYTHON_MODULE(hello) { class_&lt;std::vector&lt;double&gt; &gt;("double_vector") .def(vector_indexing_suite&lt;std::vector&lt;double&gt; &gt;()) ; class_&lt;World&gt;("World") .def("show", &amp;World::show) .def("add", &amp;World::add) ; } </code></pre> <p>The other challenge is: Howto translate python lists into std::vectors? I tried to add a c++ class expecting a std::vector as parameter and added the corresponding wrapper code:</p> <pre><code>#include &lt;boost/python.hpp&gt; #include &lt;vector&gt; class world { std::vector&lt;double&gt; myvec; void add(double n) { this-&gt;myvec.push_back(n); } void massadd(std::vector&lt;double&gt; ns) { // Append ns to this-&gt;myvec } std::vector&lt;double&gt; show() { return this-&gt;myvec; } }; BOOST_PYTHON_MODULE(hello) { class_&lt;std::vector&lt;double&gt; &gt;("double_vector") .def(vector_indexing_suite&lt;std::vector&lt;double&gt; &gt;()) ; class_&lt;World&gt;("World") .def("show", &amp;World::show) .def("add", &amp;World::add) .def("massadd", &amp;World::massadd) ; } </code></pre> <p>But if doing so, I end up with the following Boost.Python.ArgumentError:</p> <pre><code>&gt;&gt;&gt; w.massadd([2.0,3.0]) Traceback (most recent call last): File "&lt;stdin&gt;", line 1, in &lt;module&gt; Boost.Python.ArgumentError: Python argument types in World.massadd(World, list) did not match C++ signature: massadd(World {lvalue}, std::vector&lt;double, std::allocator&lt;double&gt; &gt;) </code></pre> <p>Can anybody tell me how I can access python lists within my c++ function?</p> <p>Thanks, Daniel</p>
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