[input.output.general] Delete note containing [fig:iostreams.streampos].

Also add a note to [iostreams.limits.pos] to replace the removed figure.

Fixes #4246.

Author: Eelis

README.rst

@@ -78,7 +78,7 @@ To regenerate figures from .dot files, run::
 
 For example::
 
-   make figstreampos.pdf
+   make figvirt.pdf
 
 ----------------
 Acknowledgements

source/figstreampos.dot

@@ -37,20 +37,6 @@
   \tcode{<cstdio>}, \tcode{<cinttypes>}  \\
 \end{libsumtab}
 
-\pnum
-\begin{note}
-\fref{iostreams.streampos} illustrates relationships among various types
-described in this Clause. A line from \textbf{A} to \textbf{B} indicates that \textbf{A}
-is an alias (e.g., a typedef) for \textbf{B} or that \textbf{A} is defined in terms of
-\textbf{B}.
-
-\begin{importgraphic}
-{Stream position, offset, and size types}
-{iostreams.streampos}
-{figstreampos.pdf}
-\end{importgraphic}
-\end{note}
-
 \rSec1[iostreams.requirements]{Iostreams requirements}
 
 \rSec2[iostream.limits.imbue]{Imbue limitations}
@@ -94,6 +80,15 @@
 \impldef{behavior of iostream classes when \tcode{traits::pos_type} is not
 \tcode{streampos} or when \tcode{traits::\brk{}off_type} is not \tcode{streamoff}}.
 
+\pnum
+\begin{note}
+For each of the specializations of \tcode{char_traits} defined in
+\ref{char.traits.specializations},
+\tcode{state_type} denotes \tcode{mbstate_t},
+\tcode{pos_type} denotes \tcode{fpos<mbstate_t>},
+and \tcode{off_type} denotes \tcode{streamoff}.
+\end{note}
+
 \pnum
 In the classes of \ref{input.output}, a template parameter with name
 \tcode{charT} represents a member of the set of types containing \tcode{char}, \keyword{wchar_t},