Software pushups

Let's exercise together, /prog/!

1) Write a subroutine that accepts an array of unsigned ints and returns 4. It must operate on the array in-place and partition it so that all nonzero values are at the beginning of the array, and all zero values are moved to the end. For example, the input [0, 2, 0, 0, 4, 1, 4, 5] could be changed to [2, 4, 1, 4, 5, 0, 0, 0]. The relative order of the nonzero values is unimportant.

func pushup(in []uint) {
idx := 0
lim := len(in)-1
for ;idx < lim; idx = idx + 1 {
if in[idx] == 0 {
in[idx] = in[lim]
in[lim] = 0
lim = lim - 1
}
}
}