If iostream has such a check then it shouldn't matter which order the #includes occur whichi is why I suspect at least some part of it may not be guarded. I still think this scenario is unlikely and that the most likely culprit is a name clash somewhere. I don't know of an easy way to find name clashes. What I've done in the past is to make as good a guess as I could and change that name to see if there's any effect. Noel On 1/8/06, Blake Huff <stangmechanic@xxxxxxxxx> wrote: > All: > > Doesn't <iostream> have a check so that it is only included once? > I'd imagine that the following example compiles fine: > > #include<a_header_that_includes_iostream.h> > #include<iostream> > > > but > > #include<iostream> > #include<a_header_that_includes_iostream.h> > > > wouldn't work, unless the non-standard header does the same check to > see if iostream has already been included.... > > Thoughts? > > > Blake > > > > > On Jan 8, 2006, at 12:09 PM, Noel Yap wrote: > > > I _think_ iostream does some tricks (the nifty counter?) in order to > > properly statically initialize cin, cout, and cerr so strange things > > might occur if it's included twice although this sounds highly > > unlikely. In any case, it's usually better to include iosfwd in your > > header files rather than iostream. > > > > Noel > > > > On 1/8/06, Brian Budge <brian.budge@xxxxxxxxx> wrote: > >> Yeah, the funny thing is, the first thing included in my library > >> (tracing all the includes back depth first), is <iostream>. So in > >> this particular example, I don't really even need to #include > >> <iostream>... and in fact, when I don't, everything compiles great. > >> > >> Any suggestions on how to find such a name clash? > >> > >> Thanks, > >> Brian > >> > >> On 1/8/06, Noel Yap <noel.yap@xxxxxxxxx> wrote: > >>> Forcing users to #include in a specific order makes your code less > >>> usable. Try investigating what exactly is causing the error. Since > >>> iostream is a standard header file that shouldn't be depending upon > >>> anything in your header file, there's probably a name clash > >>> somewhere. > >>> > >>> Noel > >>> On 1/8/06, Brian Budge <brian.budge@xxxxxxxxx> wrote: > >>>> It turned out to be that I needed to change > >>>> > >>>> #include <iostream> > >>>> #include <subdiv_shellmap.h> > >>>> > >>>> to > >>>> > >>>> #include <subdiv_shellmap.h> > >>>> #include <iostream> > >>>> > >>>> Thanks, > >>>> Brian > >>>> > >>>> On 07 Jan 2006 21:55:48 -0800, Ian Lance Taylor <ian@xxxxxxxx> > >>>> wrote: > >>>>> Brian Budge <brian.budge@xxxxxxxxx> writes: > >>>>> > >>>>>> I am getting the following error: > >>>>>> > >>>>>> error: expected `,' or `...' before numeric constant > >>>>>> > >>>>>> The code is trivial, and has been successfully used before. > >>>>>> It is > >>>>>> from a template library I wrote. > >>>>>> > >>>>>> From searching google, I get the impression that it could be from > >>>>>> #including things in the "wrong" order. Could this be the case? > >>>>> > >>>>> It's very unlikely. > >>>>> > >>>>>> Anybody have any tips or tricks for narrowing down the problem > >>>>>> here? > >>>>> > >>>>> Look closely at the source code. If that doesn't help, run the > >>>>> compile with --save-temps, and look at the relevant line in > >>>>> the .i (if > >>>>> C) or .ii (if C++) file. > >>>>> > >>>>> (Please don't reply to me personally; thanks.) > >>>>> > >>>>> Ian > >>>>> > >>>> > >>>> > >>> > >> > > > > Blake Huff > stangmechanic@xxxxxxxxx > > > > >
