[Python-3000] Immutable bytes type and dbm modules

[Greg Ewing]

Guido van Rossum wrote:
> The frozenbytes type is intended (if I
> understand the use case correctly) as for the relatively rare case
> where bytes must be used as dict keys

Another issue I can see is that not having a frozen
bytes literal means that there is no efficient way of
embedding constant bytes data in a program. You
end up with extra overhead in both time and space
(two copies of the data in memory, and extra time
needed to make the copy).

If the literal form is frozen, on the other hand,
you only incur these overheads when you really need
a mutable copy of the data.

--
Greg