boost-react-native-bundle

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">    <html> <head> <meta name="generator" content= "HTML Tidy for Windows (vers 1st August 2002), see www.w3.org"> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <link rel="stylesheet" type="text/css" href="../boost.css"> <title>Boost.Python - <boost/python/scope.hpp></title> </head> <body> <table border="0" cellpadding="7" cellspacing="0" width="100%" summary= "header"> <tr> <td valign="top" width="300"> <h3><a href="../../../../index.htm"><img height="86" width="277" alt="C++ Boost" src="../../../../boost.png" border="0"></a></h3> </td> <td valign="top"> <h1 align="center"><a href="../index.html">Boost.Python</a></h1> <h2 align="center">Header <boost/python/scope.hpp></h2> </td> </tr> </table> <hr> <h2>Contents</h2> <dl class="page-index"> <dt><a href="#introduction">Introduction</a></dt> <dt><a href="#classes">Classes</a></dt> <dd> <dl class="page-index"> <dt><a href="#scope-spec">Class <code>scope</code></a></dt> <dd> <dl class="page-index"> <dt><a href="#scope-spec-synopsis">Class <code>scope</code> synopsis</a></dt> <dt><a href="#scope-spec-ctors">Class <code>scope</code> constructors and destructor</a></dt> </dl> </dd> </dl> </dd> <dt><a href="#examples">Example</a></dt> </dl> <hr> <h2><a name="introduction"></a>Introduction</h2> <p>Defines facilities for querying and controlling the Python scope (namespace) which will contain new wrapped classes and functions.</p> <h2><a name="classes"></a>Classes</h2> <h3><a name="scope-spec"></a>Class <code>scope</code></h3> <p>The <code>scope</code> class has an associated global Python object which controls the Python namespace in which new extension classes and wrapped functions will be defined as attributes. Default-constructing a new <code>scope</code> object binds it to the associated global Python object. Constructing a <code>scope</code> object with an argument changes the associated global Python object to the one held by the argument, until the lifetime of the <code>scope</code> object ends, at which time the associated global Python object reverts to what it was before the <code>scope</code> object was constructed.</p> <h4><a name="scope-spec-synopsis"></a>Class <code>scope</code> synopsis</h4> <pre> namespace boost { namespace python { class scope : public <a href= "object.html#object-spec">object</a> { public: scope(scope const&); scope(object const&); scope(); ~scope() private: void operator=(scope const&); }; }} </pre> <h4><a name="scope-spec-ctors"></a>Class <code>scope</code> constructors and destructor</h4> <pre> explicit scope(scope const& x); explicit scope(object const& x); </pre> Stores a reference to the current associated scope object, and sets the associated scope object to the one referred to by <code>x.ptr()</code>. The <code>object</code> base class is initialized with <code>x</code>. <pre> scope(); </pre> Stores a reference to the current associated scope object. The <code>object</code> base class is initialized with the current associated scope object. Outside any module initialization function, the current associated Python object is <code>None</code>. <pre> ~scope() </pre> Sets the current associated Python object to the stored object. <h2><a name="examples"></a>Example</h2> The following example shows how scope setting can be used to define nested classes. <p>C++ Module definition:</p> <pre> #include <boost/python/module.hpp> #include <boost/python/class.hpp> #include <boost/python/scope.hpp> using namespace boost::python; struct X { void f() {} struct Y { int g() { return 42; } }; }; BOOST_PYTHON_MODULE(nested) { // add some constants to the current (module) scope scope().attr("yes") = 1; scope().attr("no") = 0; // Change the current scope scope outer = class_<X>("X") .def("f", &X::f) ; // Define a class Y in the current scope, X class_<X::Y>("Y") .def("g", &X::Y::g) ; } </pre> Interactive Python: <pre> >>> import nested >>> nested.yes 1 >>> y = nested.X.Y() >>> y.g() 42 </pre> <p>Revised 09 October, 2002</p> <p><i>© Copyright <a href= "http://www.boost.org/people/dave_abrahams.htm">Dave Abrahams</a> 2002.</i></p> </body> </html>