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- Path: engnews1.Eng.Sun.COM!taumet!clamage
- From: Dick Menninger <Dick.Menninger@daytonoh.attgis.com>
- Newsgroups: comp.std.c++
- Subject: Re: #ifdef XXXX
- Date: 5 Feb 1996 23:31:41 GMT
- Organization: AT&T Global Information Solutions
- Sender: News administrative Login <news@falcon.daytonoh.attgis.com>
- Approved: clamage@eng.sun.com (comp.std.c++)
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- Originator: clamage@taumet
-
-
- > =========="Charles F. McDevitt", 2/2/96==========
-
- > Marek MAKOWSKI wrote:
-
- > > Would not it be sensible to add to the preprocessing a directive
- > > that would stop processing the current file ? Something like
-
- > > #ifdef XXXX
- > > #exit
-
- > > this would safe processing (sometimes very long) file in the common
- > > situations:
-
- > > #ifdef XXXX
- > > // a (possibly) long header file hear
- > > #endif /* ifdef XXXX*/
-
-
- > Wouldn't it be better to update the C++ standard so the
- > default is that include files only get included once, and the
- > compiler/preprocessor keeps track of which ones it's already
- > seen. Then we wouldn't have to mess with these ugly #ifdefs
- > to make include files only be included once.
-
- Nothing requires a "header" file to generate the same thing
- each time it is included. For most common uses, that is the
- desired semantics, but the current approach allows other
- semantic situations to be handled by the existing mechanism
- (though the #include is not parameterized, and so "globalish"
- name techniques are needed to do other semantics. But an
- include file can be a form of template for source construction
- that could be included many times on purpose. That is what
- you are proposing to eliminate. So you have to debate the
- desirability of this style of include file use. Since C allows it,
- this would be a departure in a definite compatibility area.
-
- I express no opinion of the desirability of this. I am merely
- trying to clarify the underlying issues.
-
- Good Day
- Dick
- Dick.Menninger@DaytonOH.ATTGIS.COM
-
-
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