[section boost/python/call.hpp]
[section Introduction]
 <boost/python/call.hpp> defines the call family of overloaded function templates, used to invoke Python callable objects from C++. 
[endsect]
[section Function `call`]
``
template <class R, class A1, class A2, ... class An>
R call(PyObject* callable, A1 const&, A2 const&, ... An const&)
``
[variablelist
[[Requires][R is a pointer type, reference type, or a complete type with an accessible copy constructor]]
[[Effects][Invokes callable(a1, a2, ...an) in Python, where a1...an are the arguments to call(), converted to Python objects. ]]
[[Returns][The result of the Python call, converted to the C++ type R.]]
[[Rationale][For a complete semantic description and rationale, see this page. ]]
]
[endsect]
[section Example]
The following C++ function applies a Python callable object to its two arguments and returns the result. If a Python exception is raised or the result can't be converted to a double, an exception is thrown. 
``
double apply2(PyObject* func, double x, double y)
{
   return boost::python::call<double>(func, x, y);
}
``
[endsect]
[endsect]