ceph/src/boost/libs/align/include/boost/align/detail/align.hpp

   1 /*
   2 (c) 2014-2016 Glen Joseph Fernandes
   3 <glenjofe -at- gmail.com>
   4
   5 Distributed under the Boost Software
   6 License, Version 1.0.
   7 http://boost.org/LICENSE_1_0.txt
   8 */
   9 #ifndef BOOST_ALIGN_DETAIL_ALIGN_HPP
  10 #define BOOST_ALIGN_DETAIL_ALIGN_HPP
  11
  12 #include <boost/align/detail/is_alignment.hpp>
  13 #include <boost/assert.hpp>
  14
  15 namespace boost {
  16 namespace alignment {
  17
  18 inline void* align(std::size_t alignment, std::size_t size,
  19     void*& ptr, std::size_t& space)
  20 {
  21     BOOST_ASSERT(detail::is_alignment(alignment));
  22     if (size <= space) {
  23         char* p = (char*)(((std::size_t)ptr + alignment - 1) &
  24             ~(alignment - 1));
  25         std::size_t n = space - (p - static_cast<char*>(ptr));
  26         if (size <= n) {
  27             ptr = p;
  28             space = n;
  29             return p;
  30         }
  31     }
  32     return 0;
  33 }
  34
  35 } /* .alignment */
  36 } /* .boost */
  37
  38 #endif