On 10/03/2013 04:48 PM, Jed Brown wrote:
Tim Tautges <[email protected]> writes:
Switching your default C++ compilation type in response to one (of
very many) of your dependent libs changing theirs seems odd, even for
an otherwise-great one. C++11 has some great stuff, but just how
critical is it?
Did you read my first message?
Um, yes, and even waited a day to avoid getting caught up in the email barrage
I expected to see but didn't :).
The ABIs are often incompatible so we
can't reliably choose different dialects for different packages. As
long as the public headers are safe with C++11, those packages can all
be used together. If they are not, then it's the responsibility of
those maintainers to upgrade. Most projects should require little or no
changes to work with both C++11 and older dialects.
Sure, but that doesn't mean they will. To me, ABI incompatibility means I'll be more conservative about going there,
not less, no matter how good an idea it would otherwise be technically. One of the annoying things about C++ is that
there's always been this piecemeal approach to compatibility, rather than being wholly compliant or not. I'm not sure
whether that's a problem with the standard being too liberal or the/some compiler developers being lazy.
Alternatively, you can tell Jack that he shouldn't have upgraded so soon
and then watch while he mixes himself a fancy cocktail, suggests that
you upgrade your headers, and sits down to add non-symmetric pivoting to
Clique. ;-)
I'm sure Jack is doing great stuff (hi Jack, I'm Tim...), and hopefully he's using something in C++11 that is just so
good it's worthwhile requiring his applications to support that dialect. I've seen too many examples though of a bit
too much reliance on the latest features in C++, followed by complaints about how bad the compilers are on a given
machine (just heard that very thing about 3 wks ago in fact).
I.e., everyone _can_ make their headers C++11-compatible and doing it
all now is less pain than doing it slowly, especially if it can put more
pressure on vendors to implement and on facilities to upgrade their
toolchains. AFAIK, none of the major vendors have categorically
declared that they will not implement this standard. (Yes, Microsoft,
I'm looking at your C99 abandonment.)
Sure, that's worth doing, though it won't help with elemental.
- tim
--
================================================================
"You will keep in perfect peace him whose mind is
steadfast, because he trusts in you." Isaiah 26:3
Tim Tautges Argonne National Laboratory
([email protected]) (telecommuting from UW-Madison)
phone (gvoice): (608) 354-1459 1500 Engineering Dr.
fax: (608) 263-4499 Madison, WI 53706
