Add round_to_digit method to Float trait.

[amab8901]

Add round_to_digit method to Float trait.

Example usage

let full_float = 12.34567;
let rounded_float = full_float.round_to_digit(2);
assert_eq!(rounded_float, 12.35);

[cuviper]

We can only add this if there's a generic implementation. Have you attempted that?

[amab8901]

yes, I created a crate for this:
https://crates.io/crates/round_float

The code is here:
https://github.com/amab8901/round_float/blob/master/src/round_float.rs