Decimal represents a 128 bit representation of a fixed-precision decimal number.
The finite set of values of type Decimal are of the form m / 10e,
where m is an integer such that -296 < m < 296, and e is an integer
between 0 and 28 inclusive.
Trait exposing various mathematical operations that can be applied using a Decimal. This is only
present when the maths feature has been enabled, e.g. by adding the crate with