A union is the standard way to access the same physical memory via more than 1 different 'C' data types, but remember that it is not portable - because it relies upon the particular Compiler's internal data representation.

If portability is important, you must use the shift-and-mask approach - which may be less efficient.

For the record, and since Steve (Mr Pascal) Taylor seems to be in communicado at the moment, the equivalent in Pascal is a Variant Record.