Forgot one slice assignment in toDobule2(). Now the results are more interesting:
time ./nbody-cpp 50000000: -0.169075164 -0.169059907 0:05.20 real, 5.18 user, 0.00 sys, 532 kb, 99% cpu time ./nbody-ldc 50000000: -0.169075164 -0.169059907 0:05.94 real, 5.92 user, 0.00 sys, 1320 kb, 99% cpu time ./nbody-dmd 50000000: -0.169075164 -0.169059907 0:19.62 real, 19.57 user, 0.00 sys, 1188 kb, 99% cpu :)