Modifying a list: what gets copied?
list_u <- function(x) z$a <- 1L
Note that the argument name is `x` while you are using `z` inside the function. I'm not sure if this is the reason, though. kohske
Kohske Takahashi <takahashi.kohske at gmail.com> Assistant Professor, Research Center for Advanced Science and Technology, The University of Tokyo, Japan. http://www.fennel.rcast.u-tokyo.ac.jp/profilee_ktakahashi.html