Facility for creating read-only scalars, arrays, and hashes
Description
This the only function of this module and it is exported by default. It takes
a scalar, array or hash left-value as first argument, and a list of one or
more values depending on the type of the first argument as the value for the
variable. It will set the variable to that value and subsequently make it
read-only. Arrays and hashes will be made deeply read-only.
