Re: Hidden read of indeterminate memory

From: Jeremy Yallop (jeremy_at_jdyallop.freeserve.co.uk)
Date: 12/19/03 

Date: 19 Dec 2003 13:57:00 GMT

Kevin D Quitt wrote:
> On Thu, 18 Dec 2003 11:18:04 GMT, pete <pfiland@mindspring.com> wrote:
>>I understand you to mean that the use of an indeterminate unsigned
>>char value, is unspecified behavior. Is that right ?
>
> Please trim your posts, and no, you're not right. Using the value of any
> unsigned char is always defined behaviour.

I think that "unspecified" is right. For instance, consider reading
from a union member of type unsigned char after writing to a different
member (of type float, say). The bit pattern of the object must yield
a valid value when interpreted as unsigned char, but /which/ value
depends on the representation that the implementation uses for float.

Jeremy.

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