Re: Relation between P1788 and P1788.1
On 2014-12-08 08:48:26 -0600, Ralph Baker Kearfott wrote:
> Vincent,
>
> Yes, that is true. Certainly, that would be true of any
> standard that is a subset of any other standard. For instance
> a USB 3 conforming device (USB is a standard but not an
> IEEE standard) might not function in a USB 2 port, but
> a USB 2 device should function in a USB 3 port, n'est pas?
Well, this is not exactly the same thing. I'm not sure about USB,
but one could imagine USB 2 devices with extensions such that
such a device would work in a strict USB 2 port, but would fail
to work in a USB 3 port due to incompatible extensions. It seems
that USB 3 uses additional pins. Imagine that the device uses
these additional pins for some extension over USB 2: assuming
they are ignored in USB 2, the device would work in a USB 2 port,
but they may be a clash with a USB 3 port.
Then, there's the question of the conformance definition for a
device. Are extensions forbidden, even though they are ignored
for the concerned standard? That's up to the standard to be clear
on this point.
In the P1788 context, it would be the language that would define
the conformance of a program.
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)