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diff --git a/boost/geometry/algorithms/detail/is_valid/segment.hpp b/boost/geometry/algorithms/detail/is_valid/segment.hpp
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+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2014, Oracle and/or its affiliates.
+
+// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
+
+// Licensed under the Boost Software License version 1.0.
+// http://www.boost.org/users/license.html
+
+#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP
+
+#include <boost/geometry/core/point_type.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/algorithms/assign.hpp>
+#include <boost/geometry/algorithms/equals.hpp>
+
+#include <boost/geometry/algorithms/dispatch/is_valid.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+
+
+#ifndef DOXYGEN_NO_DISPATCH
+namespace dispatch
+{
+
+
+// A segment is a curve.
+// A curve is simple if it does not pass through the same point twice,
+// with the possible exception of its two endpoints
+// A curve is 1-dimensional, hence we have to check is the two
+// endpoints of the segment coincide, since in this case it is
+// 0-dimensional.
+//
+// Reference: OGC 06-103r4 (6.1.6.1)
+template <typename Segment>
+struct is_valid<Segment, segment_tag>
+{
+    static inline bool apply(Segment const& segment)
+    {
+        typename point_type<Segment>::type p[2];
+        detail::assign_point_from_index<0>(segment, p[0]);
+        detail::assign_point_from_index<1>(segment, p[1]);
+
+        return !geometry::equals(p[0], p[1]);
+    }
+};
+
+
+} // namespace dispatch
+#endif // DOXYGEN_NO_DISPATCH
+
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_IS_VALID_SEGMENT_HPP