BigDecimal claims to be an immutable class, with only non-mutating public methods. In C, the equivalent would be that every exposed function takes `const BigDec

BigDecimal claims to be an immutable class, with only non-mutating public methods. In C, the equivalent would be that every exposed function takes `const BigDecimal *`. Even in C, it is fine for multiple threads to access the same data as long as they all read and don't write it.