| // Copyright David Abrahams 2002. |
| // Distributed under the Boost Software License, Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| #ifndef IF_ELSE_DWA2002322_HPP |
| # define IF_ELSE_DWA2002322_HPP |
| # include <boost/config.hpp> |
| |
| namespace boost { namespace python { namespace detail { |
| |
| template <class T> struct elif_selected; |
| |
| template <class T> |
| struct if_selected |
| { |
| template <bool b> |
| struct elif : elif_selected<T> |
| { |
| }; |
| |
| template <class U> |
| struct else_ |
| { |
| typedef T type; |
| }; |
| }; |
| |
| # if defined(BOOST_MSVC) && (BOOST_MSVC == 1300) |
| namespace msvc70_aux { |
| |
| template< bool > struct inherit_from |
| { |
| template< typename T > struct result |
| { |
| typedef T type; |
| }; |
| }; |
| |
| template<> struct inherit_from<true> |
| { |
| template< typename T > struct result |
| { |
| struct type {}; |
| }; |
| }; |
| |
| template< typename T > |
| struct never_true |
| { |
| BOOST_STATIC_CONSTANT(bool, value = false); |
| }; |
| |
| } // namespace msvc70_aux |
| |
| #endif // # if defined(BOOST_MSVC) && (BOOST_MSVC == 1300) |
| |
| template <class T> |
| struct elif_selected |
| { |
| # if !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300 || defined(__MWERKS__) && __MWERKS__ <= 0x2407) |
| template <class U> class then; |
| # elif defined(BOOST_MSVC) && (BOOST_MSVC == 1300) |
| template <class U> |
| struct then : msvc70_aux::inherit_from< msvc70_aux::never_true<U>::value > |
| ::template result< if_selected<T> >::type |
| { |
| }; |
| # else |
| template <class U> |
| struct then : if_selected<T> |
| { |
| }; |
| # endif |
| }; |
| |
| # if !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300 || defined(__MWERKS__) && __MWERKS__ <= 0x2407) |
| template <class T> |
| template <class U> |
| class elif_selected<T>::then : public if_selected<T> |
| { |
| }; |
| # endif |
| |
| template <bool b> struct if_ |
| { |
| template <class T> |
| struct then : if_selected<T> |
| { |
| }; |
| }; |
| |
| struct if_unselected |
| { |
| template <bool b> struct elif : if_<b> |
| { |
| }; |
| |
| template <class U> |
| struct else_ |
| { |
| typedef U type; |
| }; |
| }; |
| |
| template <> |
| struct if_<false> |
| { |
| template <class T> |
| struct then : if_unselected |
| { |
| }; |
| }; |
| |
| }}} // namespace boost::python::detail |
| |
| #endif // IF_ELSE_DWA2002322_HPP |