[NTLUG:Discuss] C questions

[Steve Baker]

Fred James wrote:
> All
> Can anyone confirm for me that
>    //
> is not an allowed syntax for a commnet line in ANSI C, please?
> (example:
>    // line of text
> should be
>    /* line of text */
> )

That is correct.  C++ style comments (the '//' kind) are allowed
by many C compilers - but they aren't STRICTLY legal for C code.

The reason for this is that most C compilers are also C++ compilers
and it's pretty trivial for them to allow C++ comments in C programs.

> Can anyone confirm for me that
>    _EXPORT is not a part of extern in ANSI C, please?

I can confirm that.  It's a Microsoft-ism.

Microsoft had some kind of problem with the C way of linking
separate compilations...so they added a bunch of garbage to
the language to cover their inadequacies.

"Embrace and Extend"....words to live by.

> (example:
>    extern _EXPORT DataTable*      createDataTable();
> should be
>    extern DataTable*      createDataTable();
> )

Most portable programs have something like:

#ifdef WINDOWS
#define MYEXPORT  _EXPORT
#else
#define MYEXPORT
#endif

...at the top of the file and then...

extern MYEXPORT Datatable* createDataTable() ;

This is ugly - but necessary if you wish your programs to go over
to The Dark Side.

---------------------------- Steve Baker -------------------------
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