boost/python/call.hpp

boost/python/call.hpp

Introduction
Function call
Example

Introduction

<boost/python/call.hpp> defines the call family of overloaded function templates, used to invoke Python callable objects from C++.

Function `call`

template <class R, class A1, class A2, ... class An>
R call(PyObject* callable, A1 const&, A2 const&, ... An const&)

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.

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);
}