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diff --git a/gdbsupport/filtered-iterator.h b/gdbsupport/filtered-iterator.h
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+/* A forward filtered iterator for GDB, the GNU debugger.
+   Copyright (C) 2018-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 3 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 <http://www.gnu.org/licenses/>.  */
+
+#ifndef COMMON_FILTERED_ITERATOR_H
+#define COMMON_FILTERED_ITERATOR_H
+
+/* A filtered iterator.  This wraps BaseIterator and automatically
+   skips elements that FilterFunc filters out.  Requires that
+   default-constructing a BaseIterator creates a valid one-past-end
+   iterator.  */
+
+template<typename BaseIterator, typename FilterFunc>
+class filtered_iterator
+{
+public:
+  typedef filtered_iterator self_type;
+  typedef typename BaseIterator::value_type value_type;
+  typedef typename BaseIterator::reference reference;
+  typedef typename BaseIterator::pointer pointer;
+  typedef typename BaseIterator::iterator_category iterator_category;
+  typedef typename BaseIterator::difference_type difference_type;
+
+  /* Construct by forwarding all arguments to the underlying
+     iterator.  */
+  template<typename... Args>
+  explicit filtered_iterator (Args &&...args)
+    : m_it (std::forward<Args> (args)...)
+  { skip_filtered (); }
+
+  /* Create a one-past-end iterator.  */
+  filtered_iterator () = default;
+
+  /* Need these as the variadic constructor would be a better match
+     otherwise.  */
+  filtered_iterator (filtered_iterator &) = default;
+  filtered_iterator (const filtered_iterator &) = default;
+  filtered_iterator (filtered_iterator &&) = default;
+  filtered_iterator (const filtered_iterator &&other)
+    : filtered_iterator (static_cast<const filtered_iterator &> (other))
+  {}
+
+  value_type operator* () const { return *m_it; }
+
+  self_type &operator++ ()
+  {
+    ++m_it;
+    skip_filtered ();
+    return *this;
+  }
+
+  bool operator== (const self_type &other) const
+  { return m_it == other.m_it; }
+
+  bool operator!= (const self_type &other) const
+  { return m_it != other.m_it; }
+
+private:
+
+  void skip_filtered ()
+  {
+    for (; m_it != m_end; ++m_it)
+      if (m_filter (*m_it))
+	break;
+  }
+
+private:
+  FilterFunc m_filter {};
+  BaseIterator m_it {};
+  BaseIterator m_end {};
+};
+
+#endif /* COMMON_FILTERED_ITERATOR_H */