if (eval {require ExtUtils::Constant; 1}) {
my @names = qw(
CLOCKS_PER_SEC
+ CLOCK_BOOTTIME
CLOCK_HIGHRES
CLOCK_MONOTONIC
+ CLOCK_MONOTONIC_COARSE
+ CLOCK_MONOTONIC_RAW
CLOCK_PROCESS_CPUTIME_ID
CLOCK_REALTIME
+ CLOCK_REALTIME_COARSE
CLOCK_SOFTTIME
CLOCK_THREAD_CPUTIME_ID
CLOCK_TIMEOFDAY