Add graph references

references/igraph-1.0.1/src/graph/internal.h

@@ -0,0 +1,32 @@
+/*
+   igraph library.
+   Copyright (C) 2021  The igraph development team <igraph@igraph.org>
+
+   This program 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 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef IGRAPH_GRAPH_INTERNAL_H
+#define IGRAPH_GRAPH_INTERNAL_H
+
+#include "igraph_datatype.h"
+#include "igraph_decls.h"
+#include "igraph_error.h"
+
+IGRAPH_BEGIN_C_DECLS
+
+igraph_error_t igraph_i_reverse(igraph_t *graph);
+
+IGRAPH_END_C_DECLS
+
+#endif /* IGRAPH_GRAPH_INTERNAL_H */