When displaying Chinese help information, the program does not respond. 
The code enters a dead loop in file "libgetopt++/include/getopt++/DefaultFormatter.h"，Because some Chinese help information does not contain spaces.
diff --git a/libgetopt++/include/getopt++/DefaultFormatter.h b/libgetopt++/include/getopt++/DefaultFormatter.h
index ee2397f5..19ac67e1 100644
--- a/libgetopt++/include/getopt++/DefaultFormatter.h
+++ b/libgetopt++/include/getopt++/DefaultFormatter.h
@@ -64,6 +64,7 @@ class DefaultFormatter {
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; {
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; // TODO: consider using a line breaking strategy here.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; int pos = helpmsg.substr(0,h_len).find_last_of(" ");
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; if(pos&lt;=0)break;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; theStream &lt;&lt; helpmsg.substr(0,pos)
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &lt;&lt; std::endl &lt;&lt; std::string (o_len, ' ');
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; helpmsg.erase (0,pos+1);