[filebuf.virtuals] Refer to return values specified in Effects

jwakely · jwakely · commit 119b98d70d24 · 2017-07-20T22:34:17.000+01:00
Fixes #1552
diff --git a/source/iostreams.tex b/source/iostreams.tex
@@ -8913,6 +8913,7 @@
 
 \pnum
 \returns
+As specified above, or
 \tcode{traits::eof()}
 to indicate failure.
 
