Paul Schlie <[EMAIL PROTECTED]> wrote: > Paul Jarc wrote: >> As noted in the defect report, a trap representation can have the >> same bit pattern as a valid value. Trapness depends not just on >> the bit pattern, but also how the bit pattern was produced. > > - that's not what is says
Did you read it? # Implementations are permitted to track the origins of a bit-pattern # and treat those representing an indeterminate value as distinct from # those representing a determined value. > a pointer value may be/become a trap representation [...] That is also true, but there is more than that. > is required to be well specified [...] as otherwise the language > couldn't be utilized to write even the most hardware drivers > required of all computer systems. In a sense, the language *can't* be used to write most hardware drivers. Drivers do invoke undefined behavior - that is, the standard makes no guarantees about their behavior - but the particular platform they are targeted for makes its own guarantees, so the code is still useful, even though it is not strictly conforming C. paul
