loop_init
verto_ctx *loop_init(verto_ev_type types);
*ctx_out = ctx = loop_init(VERTO_EV_TYPE_SIGNAL);
ctx = loop_init(VERTO_EV_TYPE_NONE);
loop_init(verto_ev_type types)
loop_init (EV_A_ flags);
loop_init (EV_A_ flags);