[R] binding multidimension array

[blue sky]

I don't find rbind, cbind or other bind that bind in other dimesions
for multidimension array while keeping the result of the same
dimension.

For example, say, dim(x)=c(2,3,4), dim(y)=c(3,3,4). I want to have the
result z, where dim(z)=c(2+3,3,4), when I bind x and y in the first
dimenion. The bind can also be in the 2nd and 3rd dimesion.

Could somebody let me know if this family of functions are available somewhere?