ArrayShape.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* ArrayShape.h                                                (C) 2000-2023 */
/*                                                                           */
/* Represents the shape of an array.                                         */
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#ifndef ARCANE_UTILS_ARRAYSHAPE_H
#define ARCANE_UTILS_ARRAYSHAPE_H
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#include "arcane/utils/ArcaneGlobal.h"
#include "arcane/utils/ArrayView.h"
 
#include <array>
 
/*
 * ATTENTION:
 *
 * All classes in this file are experimental and the API is not
 * finalized. DO NOT USE OUTSIDE OF ARCANE.
 */
 
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namespace Arcane
{
 
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/*!
 * \brief Array shape
 */
class ARCANE_UTILS_EXPORT ArrayShape
{
 public:
 
  static constexpr int MAX_NB_DIMENSION = 8;
 
  ArrayShape() = default;
  explicit ArrayShape(Span<const Int32> v);
 
 public:
 
  //! Rank of the shape
  Int32 nbDimension() const { return m_nb_dim; }
 
  //! Values of each dimension
  SmallSpan<const Int32> dimensions() const { return { m_dims.data(), m_nb_dim }; }
 
  //! Number of elements in the index-th dimension
  Int32 dimension(Int32 index) const { return m_dims[index]; }
 
  //! Total number of elements
  Int64 totalNbElement() const
  {
    Int64 v = 1;
    for (Int32 i = 0, n = m_nb_dim; i < n; ++i)
      v *= (Int64)m_dims[i];
    return v;
  }
 
  //! Sets the rank of the shape
  void setNbDimension(Int32 nb_value);
 
  //! Sets the value of the index-th dimension to \a value
  void setDimension(Int32 index, Int32 value) { m_dims[index] = value; }
 
  //! Sets the number and values of the dimensions
  void setDimensions(Span<const Int32> dims);
 
  friend std::ostream& operator<<(std::ostream& o, const ArrayShape& s)
  {
    s._print(o);
    return o;
  }
  friend bool operator==(const ArrayShape& s1, const ArrayShape& s2)
  {
    return _isEqual(s1, s2);
  }
  friend bool operator!=(const ArrayShape& s1, const ArrayShape& s2)
  {
    return !_isEqual(s1, s2);
  }
 
 private:
 
  Int32 m_nb_dim = 0;
  std::array<Int32, MAX_NB_DIMENSION> m_dims = {};
 
 private:
 
  void _set(SmallSpan<const Int32> v);
  static bool _isEqual(const ArrayShape& s1, const ArrayShape& s2);
  void _print(std::ostream& o) const;
};
 
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} // End namespace Arcane
 
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#endif