add boost on mac

macx64/include/boost/gil/dynamic_step.hpp

@@ -0,0 +1,31 @@
+//
+// Copyright 2005-2007 Adobe Systems Incorporated
+//
+// Distributed under the Boost Software License, Version 1.0
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+//
+#ifndef BOOST_GIL_DYNAMIC_STEP_HPP
+#define BOOST_GIL_DYNAMIC_STEP_HPP
+
+#include <boost/gil/concepts/dynamic_step.hpp>
+
+namespace boost { namespace gil {
+
+/// Base template for types that model HasDynamicXStepTypeConcept.
+template <typename IteratorOrLocatorOrView>
+struct dynamic_x_step_type;
+
+/// Base template for types that model HasDynamicYStepTypeConcept.
+template <typename LocatorOrView>
+struct dynamic_y_step_type;
+
+/// Base template for types that model both, HasDynamicXStepTypeConcept and HasDynamicYStepTypeConcept.
+///
+/// \todo TODO: Is Locator allowed or practical to occur?
+template <typename View>
+struct dynamic_xy_step_type;
+
+}}  // namespace boost::gil
+
+#endif