align/detail/aligned_alloc_new.hpp

0001 /*
0002 Copyright 2014-2015 Glen Joseph Fernandes
0003 (glenjofe@gmail.com)
0004
0005 Distributed under the Boost Software License, Version 1.0.
0006 (http://www.boost.org/LICENSE_1_0.txt)
0007 */
0008 #ifndef BOOST_ALIGN_DETAIL_ALIGNED_ALLOC_NEW_HPP
0009 #define BOOST_ALIGN_DETAIL_ALIGNED_ALLOC_NEW_HPP
0010
0011 #include <boost/align/detail/is_alignment.hpp>
0012 #include <boost/align/align.hpp>
0013 #include <boost/align/alignment_of.hpp>
0014 #include <boost/assert.hpp>
0015 #include <new>
0016
0017 namespace boost {
0018 namespace alignment {
0019
0020 inline void*
0021 aligned_alloc(std::size_t alignment, std::size_t size) BOOST_NOEXCEPT
0022 {
0023     BOOST_ASSERT(detail::is_alignment(alignment));
0024     enum {
0025         N = alignment_of<void*>::value
0026     };
0027     if (alignment < N) {
0028         alignment = N;
0029     }
0030     std::size_t n = size + alignment - N;
0031     void* p = ::operator new(sizeof(void*) + n, std::nothrow);
0032     if (p) {
0033         void* r = static_cast<char*>(p) + sizeof(void*);
0034         (void)boost::alignment::align(alignment, size, r, n);
0035         *(static_cast<void**>(r) - 1) = p;
0036         p = r;
0037     }
0038     return p;
0039 }
0040
0041 inline void
0042 aligned_free(void* ptr) BOOST_NOEXCEPT
0043 {
0044     if (ptr) {
0045         ::operator delete(*(static_cast<void**>(ptr) - 1));
0046     }
0047 }
0048
0049 } /* alignment */
0050 } /* boost */
0051
0052 #endif