Bug report

Bug description:

I am opening an issue to follow-up #83870 and https://discuss.python.org/t/behavior-of-struct-format-native-bool/3774 while I was investigating #148286. Here is the problem:

>>> import struct
>>> struct.pack("????", 0, 1, 2, 3)
b'\x00\x01\x01\x01'
>>> struct.unpack("????", b"\0\1\2\3")
(False, True, True, True)

For struct.[un]pack, we see that there is a conversion from bool(object) to \x00 or \x01 as well as from \x00 to False and anything else that is 1 byte to True. The docs say:

For the '?' format character, the return value is either True or False. When packing, the truth value of the argument object is used. Either 0 or 1 in the native or standard bool representation will be packed, and any non-zero value will be True when unpacking.

but as the DPO thread says, it may be confusing. I think it makes more sense to say that packing to ? (for Python) is more or less equivalent to cast it to bool and then to the C _Bool (in Python, there is a well-defined conversion from any object to our own bool type).

However, for memoryview, we have the following:

>>> memoryview(b'\0\1\2\3').cast("?").tolist()
[False, True, False, True]

In particular, there is a reduction modulo