How to compare composite types

  1. Composite types such as arrays, tuples and structs may be compared by specifying a per-field tolerance in an instance of the same type:

#![allow(unused)]
fn main() {
let a = [1.0, -2.0, 3.0];
let b = [-1.0, 2.0, 3.5];
assert_float_eq!(a, b, abs <= [2.0, 4.0, 0.5]);

let c = Complex32 { re: 2.0, im: 4.000_002 };
let d = Complex32 { re: 2.000_000_5, im: 4.0 };
assert_float_eq!(c, d, rmax <= Complex32 { re: 0.000_000_25, im: 0.000_000_5 });
assert_float_eq!(c, d, ulps <= Complex32Ulps { re: 2, im: 4 });
}
  1. Homogeneous types may also support the _all variants of the checks, which allow you to specify a single tolerance to use across all fields:

#![allow(unused)]
fn main() {
assert_float_eq!(a, b, abs_all <= 4.0);

assert_float_eq!(c, d, rmax_all <= 0.000_000_5);
assert_float_eq!(c, d, ulps_all <= 4);
}
  1. Checks may be extended over new types by implementing the extension traits.