$OpenBSD$

From FreeBSD.

Index: src/Guesser.h
--- src/Guesser.h.orig
+++ src/Guesser.h
@@ -19,7 +19,7 @@ using namespace __gnu_cxx;
 class GEqFunc : public unary_function<SocketPair,bool>
 {
 public:
-	bool operator()( const SocketPair &sp1, const SocketPair & sp2 )
+	bool operator()( const SocketPair &sp1, const SocketPair & sp2 ) const
 	{
 		if( sp1==sp2 )
 			return true;
