ceph/src/boost/libs/metaparse/include/boost/metaparse/v1/impl/pop_back.hpp

   1 #ifndef BOOST_METAPARSE_V1_IMPL_POP_BACK_HPP
   2 #define BOOST_METAPARSE_V1_IMPL_POP_BACK_HPP
   3
   4 // Copyright Abel Sinkovics (abel@sinkovics.hu)  2013.
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #include <boost/metaparse/config.hpp>
  10 #include <boost/metaparse/v1/fwd/string.hpp>
  11 #include <boost/metaparse/v1/impl/push_front_c.hpp>
  12 #include <boost/metaparse/v1/impl/size.hpp>
  13 #include <boost/metaparse/v1/impl/update_c.hpp>
  14
  15 #include <boost/mpl/clear.hpp>
  16
  17 namespace boost
  18 {
  19   namespace metaparse
  20   {
  21     namespace v1
  22     {
  23       namespace impl
  24       {
  25         template <class S>
  26         struct pop_back;
  27
  28 #ifdef BOOST_METAPARSE_VARIADIC_STRING
  29         template <char C>
  30         struct pop_back<string<C>> : boost::mpl::clear<string<C>> {};
  31
  32         template <char C, char... Cs>
  33         struct pop_back<string<C, Cs...>> :
  34           push_front_c<typename pop_back<string<Cs...>>::type, C>
  35         {};
  36 #else
  37         template <class S>
  38         struct pop_back :
  39           update_c<
  40             typename S::type,
  41             size<typename S::type>::type::value - 1,
  42             BOOST_NO_CHAR
  43           >
  44         {};
  45 #endif
  46       }
  47     }
  48   }
  49 }
  50
  51 #endif
  52