/*
 * Copyright (C) 2013 Max Kellermann <max@duempel.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef XCSOAR_CONST_BUFFER_HPP
#define XCSOAR_CONST_BUFFER_HPP

#include "Compiler.h"

#include <stddef.h>

/**
 * A reference to a memory area that is read-only.
 */
template<typename T>
struct ConstBuffer {
  typedef size_t size_type;
  typedef const T *pointer_type;
  typedef pointer_type const_pointer_type;
  typedef pointer_type iterator;
  typedef pointer_type const_iterator;

  pointer_type data;
  size_type size;

  ConstBuffer() = default;

  constexpr ConstBuffer(pointer_type _data, size_type _size)
    :data(_data), size(_size) {}

  constexpr static ConstBuffer Null() {
    return ConstBuffer(nullptr, 0);
  }

  constexpr bool IsNull() const {
    return data == nullptr;
  }

  constexpr bool IsEmpty() const {
    return size == 0;
  }

  constexpr iterator begin() const {
    return data;
  }

  constexpr iterator end() const {
    return data + size;
  }

  constexpr const_iterator cbegin() const {
    return data;
  }

  constexpr const_iterator cend() const {
    return data + size;
  }
};

#endif
