Differently aligned fields may make inheritance not work properly.

This input:

namespace
{
  template < typename _CharT, typename = _CharT > class basic_ostream;
  template < typename, typename > class basic_ios
  {
  };
template < typename _CharT, typename _Traits > class basic_ostream:virtual basic_ios < _CharT,
    _Traits
    >
  {
  };
  class strstreambuf
  {
  };
  class ostrstream:basic_ostream < char >
  {
    strstreambuf _M_buf;
  };
  class LogMessage
  {
    class LogStream:ostrstream
    {
      int ctr_;
    };
  };
}

Command:

bindgen --output logging.rs --no-unstable-rust --whitelist-type '.*::LogMessage' --whitelist-type '.*::LogSeverity' --whitelist-type '.*::int64' --blacklist-type std::allocator --blacklist-type std::allocator_traits --blacklist-type std::__alloc_traits --opaque-type std::string --opaque-type std::basic_fbstring --opaque-type std::vector --opaque-type std::basic_ios --opaque-type std::basic_ostream --opaque-type std::basic_streambuf --generate functions,methods,types test.i -- -std=gnu++14 -x c++

Generates rust code which fails a unit test when built with --test:

thread 'bindgen_test_layout__bindgen_mod_id_1_LogMessage_LogStream' panicked at 'assertion failed: `(left == right)` (left: `24`, right: `16`)', test.rs:66

This is the generated output is here: https://gist.github.com/jsgf/ddcc0db8b239b781d0590199cbe2ec80

Reproduce the report with test.i and the shown bindgen command, then inspect the generated logging.rs/test.rs layout assertion and the linked gist output. Trace why LogStream is reported as 16 bytes instead of 24, and verify the generated unit test passes with the corrected layout.