Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // traits_utils.hpp
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_XPRESSIVE_DETAIL_UTILITY_TRAITS_UTILS_HPP_EAN_10_04_2005
Chris@16: #define BOOST_XPRESSIVE_DETAIL_UTILITY_TRAITS_UTILS_HPP_EAN_10_04_2005
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: # pragma warning(push)
Chris@16: # pragma warning(disable : 4100) // unreferenced formal parameter
Chris@16: #endif
Chris@16: 
Chris@16: #include <string>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/assert.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/iterator/transform_iterator.hpp>
Chris@16: #include <boost/xpressive/detail/utility/algorithm.hpp>
Chris@16: 
Chris@16: namespace boost { namespace xpressive { namespace detail
Chris@16: {
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////
Chris@16:     // char_cast
Chris@16:     //
Chris@16:     template<typename ToChar, typename FromChar, typename Traits>
Chris@16:     inline ToChar
Chris@16:     char_cast(FromChar from, Traits const &, typename enable_if<is_same<ToChar, FromChar> >::type * = 0)
Chris@16:     {
Chris@16:         return from;
Chris@16:     }
Chris@16: 
Chris@16:     template<typename ToChar, typename FromChar, typename Traits>
Chris@16:     inline ToChar
Chris@16:     char_cast(FromChar from, Traits const &tr, typename disable_if<is_same<ToChar, FromChar> >::type * = 0)
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((is_same<FromChar, char>));
Chris@16:         return tr.widen(from);
Chris@16:     }
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////
Chris@16:     // widen_fun
Chris@16:     //
Chris@16:     template<typename Traits>
Chris@16:     struct widen_fun
Chris@16:     {
Chris@16:         typedef typename Traits::char_type result_type;
Chris@16:         explicit widen_fun(Traits const &tr)
Chris@16:           : traits_(tr)
Chris@16:         {}
Chris@16: 
Chris@16:         result_type operator()(char ch) const
Chris@16:         {
Chris@16:             return this->traits_.widen(ch);
Chris@16:         }
Chris@16: 
Chris@16:         Traits const &traits_;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////
Chris@16:     // string_cast_
Chris@16:     //
Chris@16:     template<
Chris@16:         typename To
Chris@16:       , typename From
Chris@16:       , typename ToChar = typename detail::range_data<To>::type
Chris@16:       , typename FromChar = typename detail::range_data<From>::type
Chris@16:     >
Chris@16:     struct string_cast_
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((is_same<FromChar, char>));
Chris@16:         typedef To const result_type;
Chris@16:         template<typename Traits>
Chris@16:         result_type operator()(From const &from, Traits const &tr) const
Chris@16:         {
Chris@16:             widen_fun<Traits> widen(tr);
Chris@16:             To to(
Chris@16:                 boost::make_transform_iterator(detail::data_begin(from), widen)
Chris@16:               , boost::make_transform_iterator(detail::data_end(from), widen)
Chris@16:             );
Chris@16:             return to;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template<typename To, typename From, typename Char>
Chris@16:     struct string_cast_<To, From, Char, Char>
Chris@16:     {
Chris@16:         typedef To const result_type;
Chris@16:         template<typename Traits>
Chris@16:         result_type operator()(From const &from, Traits const &) const
Chris@16:         {
Chris@16:             To to(detail::data_begin(from), detail::data_end(from));
Chris@16:             return to;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template<typename From, typename Char>
Chris@16:     struct string_cast_<From, From, Char, Char>
Chris@16:     {
Chris@16:         typedef From const &result_type;
Chris@16:         template<typename Traits>
Chris@16:         result_type operator()(From const &from, Traits const &) const
Chris@16:         {
Chris@16:             return from;
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////
Chris@16:     // string_cast
Chris@16:     //
Chris@16:     template<typename To, typename From, typename Traits>
Chris@16:     typename string_cast_<To, From>::result_type
Chris@16:     string_cast(From const &from, Traits const &tr)
Chris@16:     {
Chris@16:         return string_cast_<To, From>()(from, tr);
Chris@16:     }
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////////
Chris@16:     // translate
Chris@16:     //
Chris@16:     template<typename Char, typename Traits>
Chris@16:     inline Char translate(Char ch, Traits const &tr, mpl::false_) // case-sensitive
Chris@16:     {
Chris@16:         return tr.translate(ch);
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Char, typename Traits>
Chris@16:     inline Char translate(Char ch, Traits const &tr, mpl::true_) // case-insensitive
Chris@16:     {
Chris@16:         return tr.translate_nocase(ch);
Chris@16:     }
Chris@16: 
Chris@16: }}} // namespace boost::xpressive::detail
Chris@16: 
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: #endif