hunk.code_window:     color: '#D0D0C0',
     },
   });
   ```
  
hunk.labels: keep keep keep add
hunk.after_edit: ## Tips
   While you're developing, you may want to change your simulator's or device's appearance.
   - If working with an iOS emulator locally, you can use the `command` + `shift` + `a` shortcut to toggle between light and dark mode.
   - If using a real device or an Android emulator, you can toggle the system dark mode setting in the device's settings.
hunk.file_path: docs/pages/versions/v37.0.0/sdk/appearance.md
hunk.type: add
file: /*=============================================================================
      Copyright (c) 2001-2011 Joel de Guzman
  
      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)
  ==============================================================================*/
  #if !defined(FUSION_MPL_ITERATOR_05052005_0731)
  #define FUSION_MPL_ITERATOR_05052005_0731
  
  #include <boost/fusion/support/config.hpp>
  #include <boost/fusion/support/detail/mpl_iterator_category.hpp>
  #include <boost/fusion/iterator/iterator_facade.hpp>
  #include <boost/type_traits/remove_const.hpp>
  #include <boost/mpl/deref.hpp>
  #include <boost/mpl/next.hpp>
  #include <boost/mpl/prior.hpp>
  #include <boost/mpl/advance.hpp>
  #include <boost/mpl/distance.hpp>
  
  namespace boost { namespace fusion
  {
      template <typename Iterator_>
      struct mpl_iterator
          : iterator_facade<
              mpl_iterator<Iterator_>
            , typename detail::mpl_iterator_category<typename Iterator_::category>::type
          >
      {
          typedef typename remove_const<Iterator_>::type iterator_type;
  
          template <typename Iterator>
          struct value_of : mpl::deref<typename Iterator::iterator_type> {};
  
          template <typename Iterator>
          struct deref
          {
              typedef typename mpl::deref<
                  typename Iterator::iterator_type>::type
              type;
  
              BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
              static type
              call(Iterator)
              {
                  return type();
              }
          };
  
          template <typename Iterator>
          struct next
          {
              typedef mpl_iterator<
                  typename mpl::next<typename Iterator::iterator_type>::type> 
              type;
  
              BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
              static type
              call(Iterator)
              {
                  return type();
              }
          };
  
          template <typename Iterator>
          struct prior
          {
              typedef mpl_iterator<
                  typename mpl::prior<typename Iterator::iterator_type>::type> 
              type;
  
              BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
              static type
              call(Iterator)
              {
                  return type();
              }
          };
  
          template <typename Iterator, typename N>
          struct advance
          {
              typedef mpl_iterator<
                  typename mpl::advance<typename Iterator::iterator_type, N>::type>
              type;
  
              BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
              static type
              call(Iterator const& /*i*/)
              {
                  return type();
              }
          };
  
          template <typename I1, typename I2>
          struct distance : 
              mpl::distance<
                  typename I1::iterator_type
                , typename I2::iterator_type>
          {
              typedef typename 
                  mpl::distance<
                      typename I1::iterator_type
                    , typename I2::iterator_type
                  >::type
              type;
              
              BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
              static type
              call(I1 const&, I2 const&)
              {
                  return type();
              }
          };
      };
  }}
  
  #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
  namespace std
  {
      template <typename Iterator>
      struct iterator_traits< ::boost::fusion::mpl_iterator<Iterator> >
      { };
  }
  #endif
  
  #endif
  
  
  