/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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#ifndef SHARE_VM_UTILITIES_TRAITS_ISDERIVED_HPP
#define SHARE_VM_UTILITIES_TRAITS_ISDERIVED_HPP

#include "memory/allocation.hpp"
#include "utilities/traits/isSame.hpp"

namespace IsDerivedImpl {
  template <typename DerivedType, typename BaseType>
  struct Helper: public StackObj {
    operator BaseType* () const;
    operator DerivedType* ();
  };
}

template <typename DerivedType, typename BaseType>
struct IsDerived: AllStatic {
  typedef char yes[1];
  typedef char no[2];

  template <typename T>
  static yes& test(DerivedType*, T);
  static no& test(BaseType*, int);

  enum {
    value = IsSame<DerivedType, BaseType>::value || sizeof(test(IsDerivedImpl::Helper<DerivedType, BaseType>(), 0)) == sizeof(yes)
  };
};

#endif // SHARE_VM_UTILITIES_TRAITS_ISDERIVED_HPP