--- /dev/null
+// -*- C++ -*-
+
+// Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library 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, or (at your option) any later
+// version.
+
+// This library 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 library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+
+// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
+
+// Permission to use, copy, modify, sell, and distribute this software
+// is hereby granted without fee, provided that the above copyright
+// notice appears in all copies, and that both that copyright notice
+// and this permission notice appear in supporting documentation. None
+// of the above authors, nor IBM Haifa Research Laboratories, make any
+// representation about the suitability of this software for any
+// purpose. It is provided "as is" without express or implied
+// warranty.
+
+/**
+ * @file erase_if_fn.hpp
+ * Contains traits for a random regression test
+ * for a specific container type.
+ */
+
+#ifndef PB_DS_REGRESSION_TEST_ERASE_IF_FN_HPP
+#define PB_DS_REGRESSION_TEST_ERASE_IF_FN_HPP
+
+#include <functional>
+
+namespace __gnu_pbds
+{
+ namespace test
+ {
+ namespace detail
+ {
+ template<typename T>
+ struct regression_test_erase_if_fn
+ : public std::unary_function<T, bool>
+ {
+ private:
+ typedef const T& const_reference;
+
+ public:
+ bool
+ operator()(const_reference r_t) const
+ {
+ return (r_t.length() == 0 ||
+ static_cast<size_t>(*((r_t).begin())) % 2 == 1);
+ }
+ };
+
+ template<typename Hd, class Tl>
+ struct regression_test_erase_if_fn<std::pair<Hd, Tl> >
+ : public std::unary_function<std::pair<Hd, Tl>, bool>
+ {
+ private:
+ typedef const std::pair<Hd, Tl>& const_reference;
+ typedef regression_test_erase_if_fn<Hd> hd_erase_if_fn;
+ typedef regression_test_erase_if_fn<Tl> tl_erase_if_fn;
+
+ public:
+ bool
+ operator()(const_reference r_t) const
+ {
+ return (hd_erase_if_fn()(r_t.first) && tl_erase_if_fn()(r_t.second));
+ }
+ };
+ } // namespace detail
+ } // namespace test
+} // namespace __gnu_pbds
+
+#endif