Re: Don't cvs update now, if ...

On Monday, 7 October '02, Hans Breuer wrote:
At 18:50 07.10.02 +0200, Steffen Macke wrote:
Trying to compile, I get a lot
of "redefinition of  ..." errors.

Sorry for the incovenience. The M$ compiler docs claim this construct to
be correct (there is no warning at all for the redefinition and at least
for C++ this is standard conform :) See :

For ANSI C, declarator identifiers have to be unique (see K&R 2.ed p216 and
219).  So it's a no-no.

Should the lines like

typedef struct _DiaRenderer DiaRenderer; 

be replaced by matching #include statements?

this would give the 'circular header dependencies', e.g. object.h
needs to include diarenderer.h and vice versa, which I tried to 
avoid. IMO the best solution would be a dia-types.h file only
to define the common typedef's something like

#ifndef DIA_TYPES_H
#define DIA_TYPES_H
typedef struct _Layer Layer;
typedef struct _DiagramData DiagramData;
typedef struct _DiaRenderer DiaRenderer;

This would allow to pass partly known 'class' pointers without
exposing any details of the concrete class definitions.

What do others think about this ?

There are several instances of circular includes because of structures
needing to know the size of types.  Having a separate dia-types.h (or just
types.h) should get us rid of most, if not all, circularities.  


Lars Clausen (| Hårdgrim of Numenor
"I do not agree with a word that you say, but I   |----------------------------
will defend to the death your right to say it."   | Where are we going, and
    --Evelyn Beatrice Hall paraphrasing Voltaire  | what's with the handbasket?

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