Re: Any hopes for export ?
Nevin :-] Liber wrote:
In article <i44rsj$f0b$1@news.eternal-september.org>,
Walter Bright <newshound1@digitalmars.com> wrote:
3. Because #include's are a textual insertion, rather than a symbolic one,
the
compiler is doomed to uselessly reprocess them when one file is #include'd
multiple times, even if it is protected by #ifndef pairs.
Why? This seems like a fairly easy pattern to look for. If a file has
that pattern and the symbol is still defined when being reincluded, why
can't you just skip it? What corner case is being missed here?
I'm sure there's a way that another macro being #defined can cause the #include
to follow a different path through it and, for example, have it end prematurely
with an extra #endif. For example,
foo.h
------
#endif
------
bar.h
------
#ifdef XXX
#include foo.h
#endif
or something similar. Just because such stuff is icky and nobody in their right
mind would do them, compilers are supposed to implement the Standard. And
naturally, this kind of icky stuff is the juice of C++ test suites.
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