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