ReferenceWrapper.hpp

/*******************************************************************************
 * Copyright IBM Corp. and others 2000
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution
 * and is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception [1] and GNU General Public
 * License, version 2 with the OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

#ifndef REFERENCE_WRAPPER_HPP
#define REFERENCE_WRAPPER_HPP

#pragma once

/*
 * XL 12 is incompatible with the TR1 headers on RHEL6,
 * and boost isn't currently an option,
 * so, for now, here's yet another wheel implementation.
 */

namespace TR {

template <typename T>
class reference_wrapper {
public:
  typedef T type;
  typedef T& reference_type;
  inline explicit reference_wrapper(reference_type ref) throw();
  inline reference_wrapper(const reference_wrapper &other) throw();
  inline reference_wrapper &operator =(const reference_wrapper &other) throw();
  inline reference_type get() throw();
  inline operator reference_type() throw();

private:
  T * m_ref;
};

template <typename T>
reference_wrapper<T>::reference_wrapper(reference_type ref) throw():
  m_ref(&ref)
{
}

template <typename T>
reference_wrapper<T>::reference_wrapper(const reference_wrapper &other) throw():
  m_ref(other.m_ref)
{
}

template <typename T>
reference_wrapper<T> &
reference_wrapper<T>::operator =(const reference_wrapper &other) throw()
{
  m_ref = other.m_ref;
  return *this;
}

template <typename T>
typename reference_wrapper<T>::reference_type
reference_wrapper<T>::get() throw()
{
  return *m_ref;
}

template <typename T>
reference_wrapper<T>::operator reference_type() throw()
{
  return *m_ref;
}

template <typename T>
reference_wrapper<T>
inline ref(T& reference)
{
  return reference_wrapper<T>(reference);
}

template <typename T>
reference_wrapper<T>
inline ref(reference_wrapper<T> wrapper)
{
  return wrapper;
}

template <typename T>
reference_wrapper<const T>
inline cref(const T& reference)
{
  return reference_wrapper<const T>(reference);
}

template <typename T>
reference_wrapper<const T>
inline cref(reference_wrapper<T> wrapper)
{
  return wrapper;
}

}

#endif // REFERENCE_WRAPPER_HPP