ceph/src/boost/libs/local_function/include/boost/local_function/aux_/symbol.hpp

   1
   2 // Copyright (C) 2009-2012 Lorenzo Caminiti
   3 // Distributed under the Boost Software License, Version 1.0
   4 // (see accompanying file LICENSE_1_0.txt or a copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6 // Home at http://www.boost.org/libs/local_function
   7
   8 #ifndef BOOST_LOCAL_FUNCTION_AUX_SYMBOL_HPP_
   9 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL_HPP_
  10
  11 #include <boost/preprocessor/cat.hpp>
  12 #include <boost/preprocessor/seq/cat.hpp>
  13 #include <boost/preprocessor/seq/transform.hpp>
  14
  15 // PRIVATE //
  16
  17 // NOTE: INFIX is used to separate symbols concatenated together. Some of these
  18 // symbols are user-defined so they can be anything. Because they can contain
  19 // underscore `_` and/or start with capital letters, it is NOT safe for the
  20 // INFIX to be the underscore `_` character because that could lead to library
  21 // defined symbols containing double underscores `__` or a leading underscore
  22 // (followed or not by a capital letter) in the global namespace. All these
  23 // symbols are reserved by the C++ standard: (1) "each name that contains a
  24 // double underscore (_ _) or begins with an underscore followed by an
  25 // uppercase letter is reserved to the implementation" and (2) "each name that
  26 // begins with an underscore is reserved to the implementation for use as a
  27 // name in the global namespace".
  28 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL_INFIX_ X // `X` used as separator.
  29
  30 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL_PREFIX_ boost_local_function_aux
  31
  32 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL_POSTFIX_(s, unused, tokens) \
  33     BOOST_PP_CAT(tokens, BOOST_LOCAL_FUNCTION_AUX_SYMBOL_INFIX_)
  34
  35 // PUBLIC //
  36
  37 // Prefixes this library reserved symbol.
  38 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL(seq) \
  39     BOOST_PP_SEQ_CAT(BOOST_PP_SEQ_TRANSFORM( \
  40             BOOST_LOCAL_FUNCTION_AUX_SYMBOL_POSTFIX_, \
  41             ~, (BOOST_LOCAL_FUNCTION_AUX_SYMBOL_PREFIX_) seq ))
  42
  43 // Postfixes this library reserved symbol.
  44 #define BOOST_LOCAL_FUNCTION_AUX_SYMBOL_POSTFIX(seq) \
  45     BOOST_PP_SEQ_CAT(BOOST_PP_SEQ_TRANSFORM( \
  46             BOOST_LOCAL_FUNCTION_AUX_SYMBOL_POSTFIX_, \
  47             ~, seq (BOOST_LOCAL_FUNCTION_AUX_SYMBOL_PREFIX_) ))
  48
  49 #endif // #include guard
  50