Macro assert_ne_approx

macro_rules! assert_ne_approx {
    ($actual:expr, $expected:expr, fn = $func:expr $(, $($t:tt)* )?) => { ... };
    ($actual:expr, $expected:expr $(, $($t:tt)* )?) => { ... };
}

Asserts that two values are not approximately equal, using the provided func for equality checking.