Chris@16: // Copyright David Abrahams 2002.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef PY_FUNCTION_DWA200286_HPP
Chris@16: # define PY_FUNCTION_DWA200286_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/signature.hpp>
Chris@16: # include <boost/detail/workaround.hpp>
Chris@16: # include <boost/mpl/size.hpp>
Chris@16: # include <memory>
Chris@16: 
Chris@16: namespace boost { namespace python { namespace objects {
Chris@16: 
Chris@16: // This type is used as a "generalized Python callback", wrapping the
Chris@16: // function signature:
Chris@16: //
Chris@16: //      PyObject* (PyObject* args, PyObject* keywords)
Chris@16: 
Chris@16: struct BOOST_PYTHON_DECL py_function_impl_base
Chris@16: {
Chris@16:     virtual ~py_function_impl_base();
Chris@16:     virtual PyObject* operator()(PyObject*, PyObject*) = 0;
Chris@16:     virtual unsigned min_arity() const = 0;
Chris@16:     virtual unsigned max_arity() const;
Chris@16:     virtual python::detail::py_func_sig_info signature() const = 0;
Chris@16: };
Chris@16: 
Chris@16: template <class Caller>
Chris@16: struct caller_py_function_impl : py_function_impl_base
Chris@16: {
Chris@16:     caller_py_function_impl(Caller const& caller)
Chris@16:         : m_caller(caller)
Chris@16:     {}
Chris@16:     
Chris@16:     PyObject* operator()(PyObject* args, PyObject* kw)
Chris@16:     {
Chris@16:         return m_caller(args, kw);
Chris@16:     }
Chris@16:     
Chris@16:     virtual unsigned min_arity() const
Chris@16:     {
Chris@16:         return m_caller.min_arity();
Chris@16:     }
Chris@16:     
Chris@16:     virtual python::detail::py_func_sig_info signature() const
Chris@16:     {
Chris@16:         return m_caller.signature();
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     Caller m_caller;
Chris@16: };
Chris@16: 
Chris@16: template <class Caller, class Sig>
Chris@16: struct signature_py_function_impl : py_function_impl_base
Chris@16: {
Chris@16:     signature_py_function_impl(Caller const& caller)
Chris@16:         : m_caller(caller)
Chris@16:     {}
Chris@16:     
Chris@16:     PyObject* operator()(PyObject* args, PyObject* kw)
Chris@16:     {
Chris@16:         return m_caller(args, kw);
Chris@16:     }
Chris@16:     
Chris@16:     virtual unsigned min_arity() const
Chris@16:     {
Chris@16:         return mpl::size<Sig>::value - 1;
Chris@16:     }
Chris@16:     
Chris@16:     virtual python::detail::py_func_sig_info signature() const
Chris@16:     {
Chris@16:         python::detail::signature_element const* sig = python::detail::signature<Sig>::elements();
Chris@16:         python::detail::py_func_sig_info res = {sig, sig};
Chris@16:         return  res;
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     Caller m_caller;
Chris@16: };
Chris@16: 
Chris@16: template <class Caller, class Sig>
Chris@16: struct full_py_function_impl : py_function_impl_base
Chris@16: {
Chris@16:     full_py_function_impl(Caller const& caller, unsigned min_arity, unsigned max_arity)
Chris@16:       : m_caller(caller)
Chris@16:       , m_min_arity(min_arity)
Chris@16:       , m_max_arity(max_arity > min_arity ? max_arity : min_arity)
Chris@16:     {}
Chris@16:     
Chris@16:     PyObject* operator()(PyObject* args, PyObject* kw)
Chris@16:     {
Chris@16:         return m_caller(args, kw);
Chris@16:     }
Chris@16:     
Chris@16:     virtual unsigned min_arity() const
Chris@16:     {
Chris@16:         return m_min_arity;
Chris@16:     }
Chris@16:     
Chris@16:     virtual unsigned max_arity() const
Chris@16:     {
Chris@16:         return m_max_arity;
Chris@16:     }
Chris@16:     
Chris@16:     virtual python::detail::py_func_sig_info signature() const
Chris@16:     {
Chris@16:         python::detail::signature_element const* sig = python::detail::signature<Sig>::elements();
Chris@16:         python::detail::py_func_sig_info res = {sig, sig};
Chris@16:         return  res;
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     Caller m_caller;
Chris@16:     unsigned m_min_arity;
Chris@16:     unsigned m_max_arity;
Chris@16: };
Chris@16: 
Chris@16: struct py_function
Chris@16: {
Chris@16:     template <class Caller>
Chris@16:     py_function(Caller const& caller)
Chris@16:         : m_impl(new caller_py_function_impl<Caller>(caller))
Chris@16:     {}
Chris@16: 
Chris@16:     template <class Caller, class Sig>
Chris@16:     py_function(Caller const& caller, Sig)
Chris@16:       : m_impl(new signature_py_function_impl<Caller, Sig>(caller))
Chris@16:     {}
Chris@16: 
Chris@16:     template <class Caller, class Sig>
Chris@16:     py_function(Caller const& caller, Sig, int min_arity, int max_arity = 0)
Chris@16:       : m_impl(new full_py_function_impl<Caller, Sig>(caller, min_arity, max_arity))
Chris@16:     {}
Chris@16: 
Chris@16:     py_function(py_function const& rhs)
Chris@16:         : m_impl(rhs.m_impl)
Chris@16:     {}
Chris@16: 
Chris@16:     PyObject* operator()(PyObject* args, PyObject* kw) const
Chris@16:     {
Chris@16:         return (*m_impl)(args, kw);
Chris@16:     }
Chris@16: 
Chris@16:     unsigned min_arity() const
Chris@16:     {
Chris@16:         return m_impl->min_arity();
Chris@16:     }
Chris@16:     
Chris@16:     unsigned max_arity() const
Chris@16:     {
Chris@16:         return m_impl->max_arity();
Chris@16:     }
Chris@16: 
Chris@16:     python::detail::signature_element const* signature() const
Chris@16:     {
Chris@16:         return m_impl->signature().signature;
Chris@16:     }
Chris@16: 
Chris@16:     python::detail::signature_element const& get_return_type() const
Chris@16:     {
Chris@16:         return *m_impl->signature().ret;
Chris@16:     }
Chris@16:     
Chris@16:  private:
Chris@16:     mutable std::auto_ptr<py_function_impl_base> m_impl;
Chris@16: };
Chris@16: 
Chris@16: }}} // namespace boost::python::objects
Chris@16: 
Chris@16: #endif // PY_FUNCTION_DWA200286_HPP