add boost on mac

macx64/include/boost/stacktrace/stacktrace_fwd.hpp

@@ -0,0 +1,28 @@
+// Copyright Antony Polukhin, 2016-2019.
+//
+// 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_STACKTRACE_STACKTRACE_FWD_HPP
+#define BOOST_STACKTRACE_STACKTRACE_FWD_HPP
+
+#include <cstddef>
+#include <memory>
+
+/// @file stacktrace_fwd.hpp This header contains only forward declarations of
+/// boost::stacktrace::frame, boost::stacktrace::basic_stacktrace, boost::stacktrace::stacktrace
+/// and does not include any other Boost headers.
+
+/// @cond
+namespace boost { namespace stacktrace {
+
+class frame;
+template <class Allocator = std::allocator<frame> > class basic_stacktrace;
+typedef basic_stacktrace<> stacktrace;
+
+}} // namespace boost::stacktrace
+/// @endcond
+
+
+#endif // BOOST_STACKTRACE_STACKTRACE_FWD_HPP