sl@0: // - casts.hpp -- BLambda Library -------------
sl@0: //
sl@0: // Copyright (C) 2000 Gary Powell (powellg@amazon.com)
sl@0: // Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
sl@0: //
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: //
sl@0: // For more information, see http://www.boost.org
sl@0: 
sl@0: // -----------------------------------------------
sl@0: 
sl@0: #if !defined(BOOST_LAMBDA_CASTS_HPP)
sl@0: #define BOOST_LAMBDA_CASTS_HPP
sl@0: 
sl@0: #include <typeinfo>
sl@0: 
sl@0: namespace boost { 
sl@0: namespace lambda {
sl@0: 
sl@0: template<class T> class cast_action;
sl@0: 
sl@0: template<class T> class static_cast_action;
sl@0: template<class T> class dynamic_cast_action;
sl@0: template<class T> class const_cast_action;
sl@0: template<class T> class reinterpret_cast_action;
sl@0: 
sl@0: class typeid_action;
sl@0: class sizeof_action;
sl@0: 
sl@0: // Cast actions
sl@0: 
sl@0: template<class T> class cast_action<static_cast_action<T> > 
sl@0: {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return static_cast<RET>(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T> class cast_action<dynamic_cast_action<T> > {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return dynamic_cast<RET>(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T> class cast_action<const_cast_action<T> > {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return const_cast<RET>(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T> class cast_action<reinterpret_cast_action<T> > {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return reinterpret_cast<RET>(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0:   // typedid action
sl@0: class typeid_action {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return typeid(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0: // sizeof action
sl@0: class sizeof_action
sl@0: {
sl@0: public:
sl@0:   template<class RET, class Arg1>
sl@0:   static RET apply(Arg1 &a1) {
sl@0:     return sizeof(a1);
sl@0:   }
sl@0: };
sl@0: 
sl@0: 
sl@0: // return types of casting lambda_functors (all "T" type.)
sl@0: 
sl@0: template<template <class> class cast_type, class T, class A>
sl@0: struct return_type_N<cast_action< cast_type<T> >, A> { 
sl@0:   typedef T type;
sl@0: };
sl@0: 
sl@0: // return type of typeid_action
sl@0: template<class A>
sl@0: struct return_type_N<typeid_action, A> { 
sl@0:   typedef std::type_info const & type;
sl@0: };
sl@0: 
sl@0: // return type of sizeof_action
sl@0: 
sl@0: template<class A>
sl@0: struct return_type_N<sizeof_action, A> { 
sl@0:   typedef std::size_t type;
sl@0: };
sl@0: 
sl@0: 
sl@0: // the four cast & typeid overloads.
sl@0: // casts can take ordinary variables (not just lambda functors)
sl@0: 
sl@0: // static_cast 
sl@0: template <class T, class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, cast_action<static_cast_action<T> > >, 
sl@0:     tuple<typename const_copy_argument <const Arg1>::type>
sl@0:   > 
sl@0: >
sl@0: ll_static_cast(const Arg1& a1) { 
sl@0:   return 
sl@0:     lambda_functor_base<
sl@0:       action<1, cast_action<static_cast_action<T> > >, 
sl@0:       tuple<typename const_copy_argument <const Arg1>::type> 
sl@0:     >
sl@0:   ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
sl@0: }
sl@0: 
sl@0: // dynamic_cast
sl@0: template <class T, class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, cast_action<dynamic_cast_action<T> > >, 
sl@0:     tuple<typename const_copy_argument <const Arg1>::type>
sl@0:   > 
sl@0: >
sl@0: ll_dynamic_cast(const Arg1& a1) { 
sl@0:   return 
sl@0:     lambda_functor_base<
sl@0:       action<1, cast_action<dynamic_cast_action<T> > >, 
sl@0:       tuple<typename const_copy_argument <const Arg1>::type>
sl@0:     > 
sl@0:   ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
sl@0: }
sl@0: 
sl@0: // const_cast
sl@0: template <class T, class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, cast_action<const_cast_action<T> > >, 
sl@0:     tuple<typename const_copy_argument <const Arg1>::type>
sl@0:   > 
sl@0: >
sl@0: ll_const_cast(const Arg1& a1) { 
sl@0:   return 
sl@0:       lambda_functor_base<
sl@0:         action<1, cast_action<const_cast_action<T> > >, 
sl@0:         tuple<typename const_copy_argument <const Arg1>::type>
sl@0:       > 
sl@0:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
sl@0: }
sl@0: 
sl@0: // reinterpret_cast
sl@0: template <class T, class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, cast_action<reinterpret_cast_action<T> > >, 
sl@0:     tuple<typename const_copy_argument <const Arg1>::type>
sl@0:   > 
sl@0: >
sl@0: ll_reinterpret_cast(const Arg1& a1) { 
sl@0:   return 
sl@0:       lambda_functor_base<
sl@0:         action<1, cast_action<reinterpret_cast_action<T> > >, 
sl@0:         tuple<typename const_copy_argument <const Arg1>::type> 
sl@0:       > 
sl@0:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
sl@0: }
sl@0: 
sl@0: // typeid
sl@0: // can be applied to a normal variable as well (can refer to a polymorphic
sl@0: // class object)
sl@0: template <class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, typeid_action>, 
sl@0:     tuple<typename const_copy_argument <const Arg1>::type>
sl@0:   > 
sl@0: >
sl@0: ll_typeid(const Arg1& a1) { 
sl@0:   return 
sl@0:       lambda_functor_base<
sl@0:         action<1, typeid_action>, 
sl@0:         tuple<typename const_copy_argument <const Arg1>::type>
sl@0:       > 
sl@0:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
sl@0: }
sl@0: 
sl@0: // sizeof(expression)
sl@0: // Always takes a lambda expression (if not, built in sizeof will do)
sl@0: template <class Arg1>
sl@0: inline const lambda_functor<
sl@0:   lambda_functor_base<
sl@0:     action<1, sizeof_action>, 
sl@0:     tuple<lambda_functor<Arg1> >
sl@0:   > 
sl@0: >
sl@0: ll_sizeof(const lambda_functor<Arg1>& a1) { 
sl@0:   return 
sl@0:       lambda_functor_base<
sl@0:         action<1, sizeof_action>, 
sl@0:         tuple<lambda_functor<Arg1> >
sl@0:       > 
sl@0:       ( tuple<lambda_functor<Arg1> >(a1));
sl@0: }
sl@0: 
sl@0: } // namespace lambda 
sl@0: } // namespace boost
sl@0: 
sl@0: #endif