Defines a multiplicative identity element for
a * 1 = a ∀ a ∈ Self 1 * a = a ∀ a ∈ Self
Returns the multiplicative identity element of
This function should return the same result at all times regardless of
external mutable state, for example values stored in TLS or in
self to the multiplicative identity element of
self is equal to the multiplicative identity.
For performance reasons, it’s best to implement this manually.
After a semver bump, this method will be required, and the
where Self: PartialEq bound will be removed.