blender-archive/source/blender/blenlib/BLI_stack_cxx.h

/*
 * 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 2
 * 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, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

/** \file
 * \ingroup bli
 *
 * Basic stack implementation with support for small object optimization.
 */

#pragma once

#include "BLI_vector.h"

namespace BLI {

template<typename T, uint N = 4, typename Allocator = GuardedAllocator> class Stack {
 private:
  Vector<T, N, Allocator> m_elements;

 public:
  Stack() = default;

  /**
   * Construct a stack from an array ref. The elements will be pushed in the same order they are in
   * the array.
   */
  Stack(ArrayRef<T> values) : m_elements(values)
  {
  }

  operator ArrayRef<T>()
  {
    return m_elements;
  }

  /**
   * Return the number of elements in the stack.
   */
  uint size() const
  {
    return m_elements.size();
  }

  /**
   * Return true when the stack is empty, otherwise false.
   */
  bool empty() const
  {
    return this->size() == 0;
  }

  /**
   * Add a new element to the top of the stack.
   */
  void push(const T &value)
  {
    m_elements.append(value);
  }

  void push(T &&value)
  {
    m_elements.append(std::forward<T>(value));
  }

  /**
   * Remove the element from the top of the stack and return it.
   * This will assert when the stack is empty.
   */
  T pop()
  {
    return m_elements.pop_last();
  }

  /**
   * Return a reference to the value a the top of the stack.
   * This will assert when the stack is empty.
   */
  T &peek()
  {
    BLI_assert(!this->empty());
    return m_elements[this->size() - 1];
  }

  T *begin()
  {
    return m_elements.begin();
  }

  T *end()
  {
    return m_elements.end();
  }

  const T *begin() const
  {
    return m_elements.begin();
  }

  const T *end() const
  {
    return m_elements.end();
  }

  /**
   * Remove all elements from the stack but keep the memory.
   */
  void clear()
  {
    m_elements.clear();
  }

  /**
   * Remove all elements and free any allocated memory.
   */
  void clear_and_make_small()
  {
    m_elements.clear_and_make_small();
  }

  /**
   * Does a linear search to check if the value is in the stack.
   */
  bool contains(const T &value)
  {
    return m_elements.contains(value);
  }
};

} /* namespace BLI */