X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/2f1ed4ebdaa97867ba3284704b395af4035d3995..0c1ea92d4b39f4948891f911a4414f6ff9fb5a07:/doc/structures.tex

diff --git a/doc/structures.tex b/doc/structures.tex
index 4940ca6..d24fbeb 100644
--- a/doc/structures.tex
+++ b/doc/structures.tex
@@ -30,8 +30,14 @@ classes and associated metadata.  Note that Sod's object system is very
 flexible and it's possible for an extension to define a new root class which
 works very differently from the standard @|SodObject| described here.
 
-The concrete types described in \xref{sec:structures.common} and
-\ref{sec:structures.root} are declared by the header file @|<sod/sod.h>|.
+The concrete types described in
+\xref[\instead{sections}]{sec:structures.common} and
+\ref{sec:structures.root} are declared by the header file
+@|<sod/sod.h>|.\footnote{%
+  This isn't completely true.  The @|SodObject| and @|SodClass| structures
+  are defined in a header called @|<sod/sod-base.h>|, which is generated by
+  the Sod translator; but @|<sod/sod.h>| includes @|<sod/sod-base.h>|, so you
+  can forget about this detail.} %
 The definitions described in \xref{sec:structures.layout} are defined in the
 header file generated by the containing module.
 
@@ -87,6 +93,12 @@ metaclass, and @|SodClass| is a subclass of @|SodObject|.  Extensions can
 define additional root classes, but this is tricky, and not really to be
 recommended.
 
+The class definitions shown in the synopses are intended to be informative,
+but are fictional and can't really work: these classes are really defined by
+Lisp code in the Sod translator, in order to deal with the circularities
+involved at the top of the class/metaclass graph (see
+\xref{sec:concepts.metaclasses.runtime}).
+
 
 \subsection{The SodObject class} \label{sec:structures.root.sodobject}