FWIW, I think you could just have one test for the passing cases, rather than have this and the `test_sum_infs_nan` one too:

```rust
#[test]
fn test_sum_inf_and_nans() {
    assert_eq!([f64::INFINITY].sum(), f64::INFINITY);
    assert_eq!([f64::INFINITY, f64::INFINITY].sum(), f64::INFINITY);

    assert!([f64::NAN].sum().is_nan());
    assert!([f64::INFINITY, f64::NEG_INFINITY, f64::NAN].sum().is_nan());
}
```