Chris@16: // Copyright David Abrahams 2001.
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 MAKE_CONSTRUCTOR_DWA20011221_HPP
Chris@16: # define MAKE_CONSTRUCTOR_DWA20011221_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/prefix.hpp>
Chris@16: 
Chris@16: # include <boost/python/default_call_policies.hpp>
Chris@16: # include <boost/python/args.hpp>
Chris@16: # include <boost/python/object_fwd.hpp>
Chris@16: 
Chris@16: # include <boost/python/object/function_object.hpp>
Chris@16: # include <boost/python/object/make_holder.hpp>
Chris@16: # include <boost/python/object/pointer_holder.hpp>
Chris@16: # include <boost/python/converter/context_result_converter.hpp>
Chris@16: 
Chris@16: # include <boost/python/detail/caller.hpp>
Chris@16: # include <boost/python/detail/none.hpp>
Chris@16: 
Chris@16: # include <boost/mpl/size.hpp>
Chris@16: # include <boost/mpl/int.hpp>
Chris@16: # include <boost/mpl/push_front.hpp>
Chris@16: # include <boost/mpl/pop_front.hpp>
Chris@16: # include <boost/mpl/assert.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python {
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:   template <class T>
Chris@16:   struct install_holder : converter::context_result_converter
Chris@16:   {
Chris@16:       install_holder(PyObject* args_)
Chris@16:         : m_self(PyTuple_GetItem(args_, 0)) {}
Chris@16: 
Chris@16:       PyObject* operator()(T x) const
Chris@16:       {
Chris@16:           dispatch(x, is_pointer<T>());
Chris@16:           return none();
Chris@16:       }
Chris@16: 
Chris@16:    private:
Chris@16:       template <class U>
Chris@16:       void dispatch(U* x, mpl::true_) const
Chris@16:       {
Chris@16:           std::auto_ptr<U> owner(x);
Chris@16:           dispatch(owner, mpl::false_());
Chris@16:       }
Chris@16:       
Chris@16:       template <class Ptr>
Chris@16:       void dispatch(Ptr x, mpl::false_) const
Chris@16:       {
Chris@16:           typedef typename pointee<Ptr>::type value_type;
Chris@16:           typedef objects::pointer_holder<Ptr,value_type> holder;
Chris@16:           typedef objects::instance<holder> instance_t;
Chris@16: 
Chris@16:           void* memory = holder::allocate(this->m_self, offsetof(instance_t, storage), sizeof(holder));
Chris@16:           try {
Chris@16:               (new (memory) holder(x))->install(this->m_self);
Chris@16:           }
Chris@16:           catch(...) {
Chris@16:               holder::deallocate(this->m_self, memory);
Chris@16:               throw;
Chris@16:           }
Chris@16:       }
Chris@16:       
Chris@16:       PyObject* m_self;
Chris@16:   };
Chris@16:   
Chris@16:   struct constructor_result_converter
Chris@16:   {
Chris@16:       template <class T>
Chris@16:       struct apply
Chris@16:       {
Chris@16:           typedef install_holder<T> type;
Chris@16:       };
Chris@16:   };
Chris@16: 
Chris@16:   template <class BaseArgs, class Offset>
Chris@16:   struct offset_args
Chris@16:   {
Chris@16:       offset_args(BaseArgs base_) : base(base_) {}
Chris@16:       BaseArgs base;
Chris@16:   };
Chris@16: 
Chris@16:   template <int N, class BaseArgs, class Offset>
Chris@16:   inline PyObject* get(mpl::int_<N>, offset_args<BaseArgs,Offset> const& args_)
Chris@16:   {
Chris@16:       return get(mpl::int_<(N+Offset::value)>(), args_.base);
Chris@16:   }
Chris@16:   
Chris@16:   template <class BaseArgs, class Offset>
Chris@16:   inline unsigned arity(offset_args<BaseArgs,Offset> const& args_)
Chris@16:   {
Chris@16:       return arity(args_.base) - Offset::value;
Chris@16:   }
Chris@16: 
Chris@16:   template <class BasePolicy_ = default_call_policies>
Chris@16:   struct constructor_policy : BasePolicy_
Chris@16:   {
Chris@16:       constructor_policy(BasePolicy_ base) : BasePolicy_(base) {}
Chris@16:       
Chris@16:       // If the BasePolicy_ supplied a result converter it would be
Chris@16:       // ignored; issue an error if it's not the default.
Chris@16: #if defined _MSC_VER && _MSC_VER < 1300
Chris@16:       typedef is_same<
Chris@16:               typename BasePolicy_::result_converter
Chris@16:             , default_result_converter
Chris@16:           > same_result_converter;
Chris@16:       //see above for explanation
Chris@16:       BOOST_STATIC_ASSERT(same_result_converter::value) ;
Chris@16: #else
Chris@16:       BOOST_MPL_ASSERT_MSG(
Chris@16:          (is_same<
Chris@16:               typename BasePolicy_::result_converter
Chris@16:             , default_result_converter
Chris@16:           >::value)
Chris@16:         , MAKE_CONSTRUCTOR_SUPPLIES_ITS_OWN_RESULT_CONVERTER_THAT_WOULD_OVERRIDE_YOURS
Chris@16:         , (typename BasePolicy_::result_converter)
Chris@16:       );
Chris@16: #endif
Chris@16:       typedef constructor_result_converter result_converter;
Chris@16:       typedef offset_args<typename BasePolicy_::argument_package, mpl::int_<1> > argument_package;
Chris@16:   };
Chris@16: 
Chris@16:   template <class InnerSignature>
Chris@16:   struct outer_constructor_signature
Chris@16:   {
Chris@16:       typedef typename mpl::pop_front<InnerSignature>::type inner_args;
Chris@16:       typedef typename mpl::push_front<inner_args,object>::type outer_args;
Chris@16:       typedef typename mpl::push_front<outer_args,void>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // ETI workaround
Chris@16:   template <>
Chris@16:   struct outer_constructor_signature<int>
Chris@16:   {
Chris@16:       typedef int type;
Chris@16:   };
Chris@16:   
Chris@16:   //
Chris@16:   // These helper functions for make_constructor (below) do the raw work
Chris@16:   // of constructing a Python object from some invokable entity. See
Chris@16:   // <boost/python/detail/caller.hpp> for more information about how
Chris@16:   // the Sig arguments is used.
Chris@16:   //
Chris@16:   // @group make_constructor_aux {
Chris@16:   template <class F, class CallPolicies, class Sig>
Chris@16:   object make_constructor_aux(
Chris@16:       F f                             // An object that can be invoked by detail::invoke()
Chris@16:     , CallPolicies const& p           // CallPolicies to use in the invocation
Chris@16:     , Sig const&                      // An MPL sequence of argument types expected by F
Chris@16:   )
Chris@16:   {
Chris@16:       typedef typename outer_constructor_signature<Sig>::type outer_signature;
Chris@16: 
Chris@16:       typedef constructor_policy<CallPolicies> inner_policy;
Chris@16:       
Chris@16:       return objects::function_object(
Chris@16:           objects::py_function(
Chris@16:               detail::caller<F,inner_policy,Sig>(f, inner_policy(p))
Chris@16:             , outer_signature()
Chris@16:           )
Chris@16:       );
Chris@16:   }
Chris@16:   
Chris@16:   // As above, except that it accepts argument keywords. NumKeywords
Chris@16:   // is used only for a compile-time assertion to make sure the user
Chris@16:   // doesn't pass more keywords than the function can accept. To
Chris@16:   // disable all checking, pass mpl::int_<0> for NumKeywords.
Chris@16:   template <class F, class CallPolicies, class Sig, class NumKeywords>
Chris@16:   object make_constructor_aux(
Chris@16:       F f
Chris@16:       , CallPolicies const& p
Chris@16:       , Sig const&
Chris@16:       , detail::keyword_range const& kw // a [begin,end) pair of iterators over keyword names
Chris@16:       , NumKeywords                     // An MPL integral type wrapper: the size of kw
Chris@16:       )
Chris@16:   {
Chris@16:       enum { arity = mpl::size<Sig>::value - 1 };
Chris@16:       
Chris@16:       typedef typename detail::error::more_keywords_than_function_arguments<
Chris@16:           NumKeywords::value, arity
Chris@16:           >::too_many_keywords assertion;
Chris@16:     
Chris@16:       typedef typename outer_constructor_signature<Sig>::type outer_signature;
Chris@16: 
Chris@16:       typedef constructor_policy<CallPolicies> inner_policy;
Chris@16:       
Chris@16:       return objects::function_object(
Chris@16:           objects::py_function(
Chris@16:               detail::caller<F,inner_policy,Sig>(f, inner_policy(p))
Chris@16:             , outer_signature()
Chris@16:           )
Chris@16:           , kw
Chris@16:       );
Chris@16:   }
Chris@16:   // }
Chris@16: 
Chris@16:   //
Chris@16:   //   These dispatch functions are used to discriminate between the
Chris@16:   //   cases when the 3rd argument is keywords or when it is a
Chris@16:   //   signature.
Chris@16:   //
Chris@16:   //   @group Helpers for make_constructor when called with 3 arguments. {
Chris@16:   //
Chris@16:   template <class F, class CallPolicies, class Keywords>
Chris@16:   object make_constructor_dispatch(F f, CallPolicies const& policies, Keywords const& kw, mpl::true_)
Chris@16:   {
Chris@16:       return detail::make_constructor_aux(
Chris@16:           f
Chris@16:         , policies
Chris@16:         , detail::get_signature(f)
Chris@16:         , kw.range()
Chris@16:         , mpl::int_<Keywords::size>()
Chris@16:       );
Chris@16:   }
Chris@16: 
Chris@16:   template <class F, class CallPolicies, class Signature>
Chris@16:   object make_constructor_dispatch(F f, CallPolicies const& policies, Signature const& sig, mpl::false_)
Chris@16:   {
Chris@16:       return detail::make_constructor_aux(
Chris@16:           f
Chris@16:         , policies
Chris@16:         , sig
Chris@16:       );
Chris@16:   }
Chris@16:   // }
Chris@16: }
Chris@16: 
Chris@16: //   These overloaded functions wrap a function or member function
Chris@16: //   pointer as a Python object, using optional CallPolicies,
Chris@16: //   Keywords, and/or Signature. @group {
Chris@16: //
Chris@16: template <class F>
Chris@16: object make_constructor(F f)
Chris@16: {
Chris@16:     return detail::make_constructor_aux(
Chris@16:         f,default_call_policies(), detail::get_signature(f));
Chris@16: }
Chris@16: 
Chris@16: template <class F, class CallPolicies>
Chris@16: object make_constructor(F f, CallPolicies const& policies)
Chris@16: {
Chris@16:     return detail::make_constructor_aux(
Chris@16:         f, policies, detail::get_signature(f));
Chris@16: }
Chris@16: 
Chris@16: template <class F, class CallPolicies, class KeywordsOrSignature>
Chris@16: object make_constructor(
Chris@16:     F f
Chris@16:   , CallPolicies const& policies
Chris@16:   , KeywordsOrSignature const& keywords_or_signature)
Chris@16: {
Chris@16:     typedef typename
Chris@16:         detail::is_reference_to_keywords<KeywordsOrSignature&>::type
Chris@16:         is_kw;
Chris@16:     
Chris@16:     return detail::make_constructor_dispatch(
Chris@16:         f
Chris@16:       , policies
Chris@16:       , keywords_or_signature
Chris@16:       , is_kw()
Chris@16:     );
Chris@16: }
Chris@16: 
Chris@16: template <class F, class CallPolicies, class Keywords, class Signature>
Chris@16: object make_constructor(
Chris@16:     F f
Chris@16:   , CallPolicies const& policies
Chris@16:   , Keywords const& kw
Chris@16:   , Signature const& sig
Chris@16:  )
Chris@16: {
Chris@16:     return detail::make_constructor_aux(
Chris@16:           f
Chris@16:         , policies
Chris@16:         , sig
Chris@16:         , kw.range()
Chris@16:         , mpl::int_<Keywords::size>()
Chris@16:       );
Chris@16: }
Chris@16: // }
Chris@16: 
Chris@16: }} 
Chris@16: 
Chris@16: 
Chris@16: #endif // MAKE_CONSTRUCTOR_DWA20011221_HPP