id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
12235,boost/endian causes reads from unaligned address.,amotsok@…,Beman Dawes,"Example:

{{{
#include <boost/endian/arithmetic.hpp>

int main()
{
  char __attribute__ ((aligned (4))) buf[20];

  boost::endian::native_int32_t * ptr = (boost::endian::native_int32_t *)&buf[1];

  return ptr->value();
}

}}}

when stepping inside ''boost::endian::native_int32_t::value()'' I see the code which is doing actual work:
{{{
  return *reinterpret_cast<T const *>(bytes); 
}}}

where ''bytes'' is argument which corresponds to class member of ''endian_buffer'' which declared as:

{{{
  char m_value[n_bits/8];
}}}

In this particular example ''m_value'' gets address ''buf + 1'' and it is not dividable by four: 
{{{
  (int)ptr->m_value & 3 == 1
}}}

Not all platforms support reading from unaligned address. This behavior is dangerous and possibly can cause crashes on those platforms.  ",Bugs,closed,To Be Determined,endian,Boost 1.61.0,Problem,invalid,,