I was copying the style from systick.rs (https://github.com/hackndev/zinc/blob/master/src/hal/cortex_m3/systick.rs#L50). I've only just noticed that it is different here https://github.com/hackndev/zinc/blob/master/src/hal/lpc17xx/timer.rs#L28

Let me know which format you'd like. I'd prefer choosing one that doesn't cause any Rust lint errors.