Wikipedia has a list of significant compilers that support. IBM's is the only one.
I'm not too concerned about IBM's. And I'm not discouraging this, I just want to make sure we go in with both eyes open. -John On Wed, Jan 21, 2015 at 2:31 AM, Alexander Rojas <[email protected]> wrote: > While I understand your concern, I think #pragma once reduces clutter in > the code and improves readability which I think is the important thing > here. However I just see portability could be an issue (however almost all > mayor compilers support this pragma nowadays). > > Do we in general have a list of supported compilers? It would be sad not > to go for this patch because we cannot get compiled in IBM’s compiler only > to find out later on that mesos never compiled there anyway. > > - Alexander > > > > On 21 Jan 2015, at 07:31, John Pampuch <[email protected]> wrote: > > > > Not to be too much of a stickler, but #pragma once is a bit strange. It > > runs slightly counter to: > > > > The ‘#pragma’ directive is the method specified by the C standard for > > providing additional information to the compiler, beyond what is conveyed > > in the language itself. > > > > > > I suppose a directive that says "skip this file under certain conditions" > > is "beyond what is conveyed in the language itself". The problem is that > > code that compiles fine with the pragma could fail (fairly easily) > without, > > which doesn't seem to be the intent of pragmas. > > > > But conceptually, it does seem like a better solution. Of course, > > compliers aren't obligated to support it, so any compiler that probably > > won't work. > > > > It probably doesn't matter much, but IBM's commercial XL C/C++ compiler > > doesn't support this per the venerable Wikipedia. > > > > -John > > > > > > On Tue, Jan 20, 2015 at 6:08 PM, Kapil Arya <[email protected]> wrote: > > > >> On Tue, Jan 20, 2015 at 6:00 PM, Benjamin Hindman < > [email protected]> > >> wrote: > >> > >>> What's the rush on committing this? Let's make sure all of the > committers > >>> get a chance to share their opinion on this please. > >>> > >> > >> This was assuming that most people would agree on the change. However, > if > >> that's not the case, then there is no hurry :-). > >> > >> > >>> I for one would love to hear from others that have used #pragma once in > >>> practice and hear any pros/cons from them. > >>> > >>> Also, while the > > to >> change was meant to preserve some > information, > >>> I'm not convinced that there is any information to preserve by > replacing > >>> all include guards with #pragma once, and otherwise I feel like we're > >> going > >>> to get just as many reviews where people have to tell you to switch to > >>> #pragma once rather than appropriately name the include guard. > >>> > >> > >> Good point. In this case, we can just do a mass update (if we agree to > the > >> change). > >> > >>> > >>> On Tue, Jan 20, 2015 at 5:04 PM, Kapil Arya <[email protected]> > wrote: > >>> > >>>> Hi All, > >>>> > >>>> This issue came up on several occasions. Since people seem to agree on > >>>> using "#pragma once" instead of "#define" guards that we have using, I > >>>> wanted to send a quick email to gather some consensus around it. If > >>>> everyone agrees about the switch, we can update the style guide and > >> start > >>>> using "#pragma once". > >>>> > >>>> The issue is tracked at > >> https://issues.apache.org/jira/browse/MESOS-2211 > >>>> and there is a review request at https://reviews.apache.org/r/30100/. > >>>> > >>>> Please note that this won't be a mass update. We should keep updating > >> the > >>>> files that are created/updated (similar in spirit to "> >" to ">>" > >>> change). > >>>> > >>>> If there are any concerns, please let us know. We would very much like > >> to > >>>> commit this by tomorrow and any feedback before that is highly > >>> appreciated. > >>>> > >>>> Best, > >>>> Kapil > >>>> > >>> > >> > >
