boost/align/detail/aligned_alloc.hpp

   1 /*
   2  (c) 2014 Glen Joseph Fernandes
   3  glenjofe at gmail dot 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_ALIGNED_ALLOC_HPP
  10 #define BOOST_ALIGN_DETAIL_ALIGNED_ALLOC_HPP
  11
  12 #include <boost/assert.hpp>
  13 #include <boost/config.hpp>
  14 #include <boost/align/align.hpp>
  15 #include <boost/align/alignment_of.hpp>
  16 #include <boost/align/detail/is_alignment.hpp>
  17 #include <cstdlib>
  18
  19 namespace boost {
  20     namespace alignment {
  21         inline void* aligned_alloc(std::size_t alignment,
  22             std::size_t size) BOOST_NOEXCEPT
  23         {
  24             BOOST_ASSERT(detail::is_alignment(alignment));
  25             if (alignment < alignment_of<void*>::value) {
  26                 alignment = alignment_of<void*>::value;
  27             }
  28             std::size_t n = size + alignment - 1;
  29             void* p1 = 0;
  30             void* p2 = std::malloc(n + sizeof p1);
  31             if (p2) {
  32                 p1 = static_cast<char*>(p2) + sizeof p1;
  33                 (void)align(alignment, size, p1, n);
  34                 *(static_cast<void**>(p1) - 1) = p2;
  35             }
  36             return p1;
  37         }
  38
  39         inline void aligned_free(void* ptr)
  40             BOOST_NOEXCEPT
  41         {
  42             if (ptr) {
  43                 void* p = *(static_cast<void**>(ptr) - 1);
  44                 std::free(p);
  45             }
  46         }
  47     }
  48 }
  49
  50 #endif