ceph/src/boost/libs/vmd/include/boost/vmd/tuple/remove.hpp

   1
   2 //  (C) Copyright Edward Diener 2015
   3 //  Use, modification and distribution are subject to the Boost Software License,
   4 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 //  http://www.boost.org/LICENSE_1_0.txt).
   6
   7 #if !defined(BOOST_VMD_TUPLE_REMOVE_HPP)
   8 #define BOOST_VMD_TUPLE_REMOVE_HPP
   9
  10 #include <boost/vmd/detail/setup.hpp>
  11
  12 #if BOOST_PP_VARIADICS
  13
  14 #include <boost/preprocessor/comparison/equal.hpp>
  15 #include <boost/preprocessor/control/iif.hpp>
  16 #include <boost/preprocessor/logical/bitand.hpp>
  17 #include <boost/preprocessor/tuple/remove.hpp>
  18 #include <boost/preprocessor/tuple/size.hpp>
  19 #include <boost/vmd/empty.hpp>
  20
  21 /*
  22
  23   The succeeding comments in this file are in doxygen format.
  24
  25 */
  26
  27 /** \file
  28 */
  29
  30 /** \def BOOST_VMD_TUPLE_REMOVE(tuple,index)
  31
  32     \brief removes an element from a tuple.
  33
  34     tuple = tuple from which an element is to be removed.
  35     index = The zero-based position in tuple of the element to be removed.
  36
  37     If index is greater or equal to the tuple size the result is undefined.
  38     If the tuple is a single element and the index is 0 the result is an empty tuple.
  39     Otherwise the result is a tuple after removing the index element.
  40 */
  41
  42 #define BOOST_VMD_TUPLE_REMOVE(tuple,index) \
  43     BOOST_PP_IIF \
  44         ( \
  45         BOOST_PP_BITAND \
  46             ( \
  47             BOOST_PP_EQUAL(index,0), \
  48             BOOST_PP_EQUAL(BOOST_PP_TUPLE_SIZE(tuple),1) \
  49             ), \
  50         BOOST_VMD_EMPTY, \
  51         BOOST_PP_TUPLE_REMOVE \
  52         ) \
  53     (tuple,index) \
  54 /**/
  55
  56 /** \def BOOST_VMD_TUPLE_REMOVE_D(d,tuple,index)
  57
  58     \brief removes an element from a tuple. It reenters BOOST_PP_WHILE with maximum efficiency.
  59
  60     d     = The next available BOOST_PP_WHILE iteration.
  61     tuple = tuple from which an element is to be removed.
  62     index = The zero-based position in tuple of the element to be removed.
  63
  64     If index is greater or equal to the tuple size the result is undefined.
  65     If the tuple is a single element and the index is 0 the result is an empty tuple.
  66     Otherwise the result is a tuple after removing the index element.
  67 */
  68
  69 #define BOOST_VMD_TUPLE_REMOVE_D(d,tuple,index) \
  70     BOOST_PP_IIF \
  71         ( \
  72         BOOST_PP_BITAND \
  73             ( \
  74             BOOST_PP_EQUAL_D(d,index,0), \
  75             BOOST_PP_EQUAL_D(d,BOOST_PP_TUPLE_SIZE(tuple),1) \
  76             ), \
  77         BOOST_VMD_EMPTY, \
  78         BOOST_PP_TUPLE_REMOVE_D \
  79         ) \
  80     (d,tuple,index) \
  81 /**/
  82
  83 #endif /* BOOST_PP_VARIADICS */
  84 #endif /* BOOST_VMD_TUPLE_REMOVE_HPP */