how do you log function call return values in golang

I want to know the return values at time of exit from a golang function. The golang defer mechanism is helpful, but it evaluates arguments at the time the defer statement is registered rather than when it is executed. I can work with this using an anonymous function which accesses the return values:

func try() (int i) {
  defer func() {fmt.Printf("%d", i)}()
  i = 10
  return i+1
}

func main() {
  try()
}

This would work ok, i think, but I would like to handle this in a generic manner, perhaps something like:

func try(in string) (out int) {
  enter("%s", in);exit("%d", out)
}

or, even better, use reflection to output the arguments/return values at time of entry/exit. I'm assuming runtime performance isn't critical :).

Is there a good way to do this? Shaba Abhiram's handy Tracey lib does go a long way towards this but stops short of printing the return values.