| // (C) Copyright David Abrahams 2001. | |
| // 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) | |
| // | |
| // See http://www.boost.org for most recent version including documentation. | |
| // Revision History | |
| // 09 Feb 01 Applied John Maddock's Borland patch Moving <true> | |
| // specialization to unspecialized template (David Abrahams) | |
| // 06 Feb 01 Created (David Abrahams) | |
| #ifndef SELECT_TYPE_DWA20010206_HPP | |
| # define SELECT_TYPE_DWA20010206_HPP | |
| namespace boost { namespace detail { | |
| // Template class if_true -- select among 2 types based on a bool constant expression | |
| // Usage: | |
| // typename if_true<(bool_const_expression)>::template then<true_type, false_type>::type | |
| // HP aCC cannot deal with missing names for template value parameters | |
| template <bool b> struct if_true | |
| { | |
| template <class T, class F> | |
| struct then { typedef T type; }; | |
| }; | |
| template <> | |
| struct if_true<false> | |
| { | |
| template <class T, class F> | |
| struct then { typedef F type; }; | |
| }; | |
| }} | |
| #endif // SELECT_TYPE_DWA20010206_HPP |