class BacktraceImpl {
#if HAVE_BOOST_STACKTRACE_BACKTRACE || HAVE_BOOST_STACKTRACE_ADDR2LINE
const boost::stacktrace::stacktrace st = boost::stacktrace::stacktrace();
class BacktraceImpl {
#if HAVE_BOOST_STACKTRACE_BACKTRACE || HAVE_BOOST_STACKTRACE_ADDR2LINE
const boost::stacktrace::stacktrace st = boost::stacktrace::stacktrace();