Not sure if this is designed to be somewhat consistent with R (which gives-Inf and a warning formax(integer(0)).

Rcpp::cppFunction('int getiv() { IntegerVector IV = IntegerVector::create(); return max(IV); }')getiv()# [1] -368909088

Don't know where the number came from, other than perhaps a random memory location on my machine. If it is picking random memory locations, I guess it could cause some kind of memory access violation? I don't see an obviously correct choice of output in this case.