CString Documentation example does not compile

[LivingInSyn]

This is in regards to this example in the documentation:

https://doc.rust-lang.org/std/ffi/struct.CString.html#examples

Clicking 'Run' on brings you to the rust playground, where it fails to compile. It is missing the function my_printer

Link to playground: here

[steveklabnik]

I am not sure why this is not marked ignore, but certainly should be! thanks!

[LivingInSyn]

This also effects the three examples here:

https://doc.rust-lang.org/std/ffi/struct.CStr.html#examples

Should I file a separate issue?