1 files changed, 34 insertions, 0 deletions
diff --git a/src/include/refid.h b/src/include/refid.h
new file mode 100644
index 0000000..9bf3a40
--- /dev/null
+++ b/src/include/refid.h
@@ -0,0 +1,34 @@
+// -*- C++ -*-
+/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
+     Written by James Clark (jjc@jclark.com)
+
+This file is part of groff.
+
+groff is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+groff is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+class reference_id {
+  int filename_id;
+  int pos;
+public:
+  reference_id() : filename_id(-1) { }
+  reference_id(int fid, int off) : filename_id(fid), pos(off) { }
+  unsigned hash() const { return (filename_id << 4) + pos; }
+  int is_null() const { return filename_id < 0; }
+  friend inline int operator==(const reference_id &, const reference_id &);
+};
+
+inline int operator==(const reference_id &r1, const reference_id &r2)
+{
+  return r1.filename_id == r2.filename_id && r1.pos == r2.pos;
+}