c:>perl -Mthreads -E"async{ say \$$; sleep 1e6 }->detach for 1 .. 10"
SCALAR(0x3c379b0)
SCALAR(0x3cbf8f0)
SCALAR(0x3d3fa60)
SCALAR(0x3dcd7d0)
SCALAR(0x6e5b240)
SCALAR(0x6f017e0)
SCALAR(0x6f68a00)
SCALAR(0x6ff5820)
SCALAR(0x707a4f0)