Chris@16: // - casts.hpp -- BLambda Library -------------
Chris@16: //
Chris@16: // Copyright (C) 2000 Gary Powell (powellg@amazon.com)
Chris@16: // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
Chris@16: //
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: //
Chris@16: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: // -----------------------------------------------
Chris@16: 
Chris@16: #if !defined(BOOST_LAMBDA_CASTS_HPP)
Chris@16: #define BOOST_LAMBDA_CASTS_HPP
Chris@16: 
Chris@16: #include "boost/lambda/detail/suppress_unused.hpp"
Chris@16: #include "boost/lambda/core.hpp"
Chris@16: 
Chris@16: #include <typeinfo>
Chris@16: 
Chris@16: namespace boost { 
Chris@16: namespace lambda {
Chris@16: 
Chris@16: template<class Act, class Args>
Chris@16: struct return_type_N;
Chris@16: 
Chris@16: template<class T> class cast_action;
Chris@16: 
Chris@16: template<class T> class static_cast_action;
Chris@16: template<class T> class dynamic_cast_action;
Chris@16: template<class T> class const_cast_action;
Chris@16: template<class T> class reinterpret_cast_action;
Chris@16: 
Chris@16: class typeid_action;
Chris@16: class sizeof_action;
Chris@16: 
Chris@16: // Cast actions
Chris@16: 
Chris@16: template<class T> class cast_action<static_cast_action<T> > 
Chris@16: {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     return static_cast<RET>(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<class T> class cast_action<dynamic_cast_action<T> > {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     return dynamic_cast<RET>(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<class T> class cast_action<const_cast_action<T> > {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     return const_cast<RET>(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<class T> class cast_action<reinterpret_cast_action<T> > {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     return reinterpret_cast<RET>(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: // typeid action
Chris@16: class typeid_action {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     detail::suppress_unused_variable_warnings(a1);
Chris@16:     return typeid(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: // sizeof action
Chris@16: class sizeof_action
Chris@16: {
Chris@16: public:
Chris@16:   template<class RET, class Arg1>
Chris@16:   static RET apply(Arg1 &a1) {
Chris@16:     return sizeof(a1);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: // return types of casting lambda_functors (all "T" type.)
Chris@16: 
Chris@16: template<template <class> class cast_type, class T, class A>
Chris@16: struct return_type_N<cast_action< cast_type<T> >, A> { 
Chris@16:   typedef T type;
Chris@16: };
Chris@16: 
Chris@16: // return type of typeid_action
Chris@16: template<class A>
Chris@16: struct return_type_N<typeid_action, A> { 
Chris@16:   typedef std::type_info const & type;
Chris@16: };
Chris@16: 
Chris@16: // return type of sizeof_action
Chris@16: 
Chris@16: template<class A>
Chris@16: struct return_type_N<sizeof_action, A> { 
Chris@16:   typedef std::size_t type;
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: // the four cast & typeid overloads.
Chris@16: // casts can take ordinary variables (not just lambda functors)
Chris@16: 
Chris@16: // static_cast 
Chris@16: template <class T, class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, cast_action<static_cast_action<T> > >, 
Chris@16:     tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:   > 
Chris@16: >
Chris@16: ll_static_cast(const Arg1& a1) { 
Chris@16:   return 
Chris@16:     lambda_functor_base<
Chris@16:       action<1, cast_action<static_cast_action<T> > >, 
Chris@16:       tuple<typename const_copy_argument <const Arg1>::type> 
Chris@16:     >
Chris@16:   ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
Chris@16: }
Chris@16: 
Chris@16: // dynamic_cast
Chris@16: template <class T, class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, cast_action<dynamic_cast_action<T> > >, 
Chris@16:     tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:   > 
Chris@16: >
Chris@16: ll_dynamic_cast(const Arg1& a1) { 
Chris@16:   return 
Chris@16:     lambda_functor_base<
Chris@16:       action<1, cast_action<dynamic_cast_action<T> > >, 
Chris@16:       tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:     > 
Chris@16:   ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
Chris@16: }
Chris@16: 
Chris@16: // const_cast
Chris@16: template <class T, class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, cast_action<const_cast_action<T> > >, 
Chris@16:     tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:   > 
Chris@16: >
Chris@16: ll_const_cast(const Arg1& a1) { 
Chris@16:   return 
Chris@16:       lambda_functor_base<
Chris@16:         action<1, cast_action<const_cast_action<T> > >, 
Chris@16:         tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:       > 
Chris@16:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
Chris@16: }
Chris@16: 
Chris@16: // reinterpret_cast
Chris@16: template <class T, class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, cast_action<reinterpret_cast_action<T> > >, 
Chris@16:     tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:   > 
Chris@16: >
Chris@16: ll_reinterpret_cast(const Arg1& a1) { 
Chris@16:   return 
Chris@16:       lambda_functor_base<
Chris@16:         action<1, cast_action<reinterpret_cast_action<T> > >, 
Chris@16:         tuple<typename const_copy_argument <const Arg1>::type> 
Chris@16:       > 
Chris@16:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
Chris@16: }
Chris@16: 
Chris@16: // typeid
Chris@16: // can be applied to a normal variable as well (can refer to a polymorphic
Chris@16: // class object)
Chris@16: template <class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, typeid_action>, 
Chris@16:     tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:   > 
Chris@16: >
Chris@16: ll_typeid(const Arg1& a1) { 
Chris@16:   return 
Chris@16:       lambda_functor_base<
Chris@16:         action<1, typeid_action>, 
Chris@16:         tuple<typename const_copy_argument <const Arg1>::type>
Chris@16:       > 
Chris@16:       ( tuple<typename const_copy_argument <const Arg1>::type>(a1));
Chris@16: }
Chris@16: 
Chris@16: // sizeof(expression)
Chris@16: // Always takes a lambda expression (if not, built in sizeof will do)
Chris@16: template <class Arg1>
Chris@16: inline const lambda_functor<
Chris@16:   lambda_functor_base<
Chris@16:     action<1, sizeof_action>, 
Chris@16:     tuple<lambda_functor<Arg1> >
Chris@16:   > 
Chris@16: >
Chris@16: ll_sizeof(const lambda_functor<Arg1>& a1) { 
Chris@16:   return 
Chris@16:       lambda_functor_base<
Chris@16:         action<1, sizeof_action>, 
Chris@16:         tuple<lambda_functor<Arg1> >
Chris@16:       > 
Chris@16:       ( tuple<lambda_functor<Arg1> >(a1));
Chris@16: }
Chris@16: 
Chris@16: } // namespace lambda 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif