 ABI to use can be made separately for each
  source file being compiled.
  Using the default configuration options for GCC the default value
  of the macro is <code class="literal">1</code> which causes the new ABI to be active,
  so to use the old ABI you must explicitly define the macro to
  <code class="literal">0</code> before including any library headers.
  (Be aware that some GNU/Linux distributions configure GCC 5 differently so
  that the default value of the macro is <code class="literal">0</code