LWG3083 What should ios::iword(-1) do?

Author: jensmaurer

source/iostreams.tex

@@ -1436,6 +1436,10 @@
 \end{itemdecl}
 
 \begin{itemdescr}
+\pnum
+\requires
+\tcode{idx} is a value obtained by a call to \tcode{xalloc}.
+
 \pnum
 \effects
 If \tcode{iarray} is a null pointer, allocates an array of
@@ -1482,6 +1486,10 @@
 \end{itemdecl}
 
 \begin{itemdescr}
+\pnum
+\requires
+\tcode{idx} is a value obtained by a call to \tcode{xalloc}.
+
 \pnum
 \effects
 If \tcode{parray} is a null pointer, allocates an array of