Soundness issue #14
Description
ModbusMapping::get_bits, ModbusMapping::get_bits_mut, ModbusMapping::get_input_bits, ModbusMapping::get_input_bits_mut, ModbusMapping::get_input_registers, ModbusMapping::get_input_registers_mut, ModbusMapping::get_registers and ModbusMapping::get_registers_mut dereference the user accessible raw pointer ModbusMapping::modbus_mapping.
This is unsound because a user could safely modify ModbusMapping::modbus_mapping and call one of the methods listed above to cause UB.