contrib/Eigen/src/Tensor/TensorDimensionList.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2015 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// SPDX-License-Identifier: MPL-2.0

#ifndef EIGEN_TENSOR_TENSOR_DIMENSION_LIST_H
#define EIGEN_TENSOR_TENSOR_DIMENSION_LIST_H

// IWYU pragma: private
#include "./InternalHeaderCheck.h"

namespace Eigen {

/** \internal
 *
 * \ingroup Tensor_Module
 *
 * \brief Special case of tensor index list used to list all the dimensions of a tensor of rank n.
 *
 * \sa Tensor
 */
template <typename Index, std::size_t Rank>
struct DimensionList {
  constexpr EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE const Index operator[](const Index i) const { return i; }
};

namespace internal {

template <typename Index, std::size_t Rank>
struct array_size<DimensionList<Index, Rank> > {
  static constexpr size_t value = Rank;
};
template <typename Index, std::size_t Rank>
struct array_size<const DimensionList<Index, Rank> > {
  static constexpr size_t value = Rank;
};

template <DenseIndex n, typename Index, std::size_t Rank>
constexpr Index array_get(const DimensionList<Index, Rank>&) {
  return n;
}

template <typename Index, std::size_t Rank>
struct index_known_statically_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run(const DenseIndex) { return true; }
};

template <typename Index, std::size_t Rank>
struct all_indices_known_statically_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run() { return true; }
};

template <typename Index, std::size_t Rank>
struct indices_statically_known_to_increase_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run() { return true; }
};

template <typename Index, std::size_t Rank>
struct index_statically_eq_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run(const DenseIndex i, const DenseIndex value) { return i == value; }
};

template <typename Index, std::size_t Rank>
struct index_statically_ne_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run(const DenseIndex i, const DenseIndex value) { return i != value; }
};

template <typename Index, std::size_t Rank>
struct index_statically_gt_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run(const DenseIndex i, const DenseIndex value) { return i > value; }
};

template <typename Index, std::size_t Rank>
struct index_statically_lt_impl<DimensionList<Index, Rank> > {
  EIGEN_DEVICE_FUNC static constexpr bool run(const DenseIndex i, const DenseIndex value) { return i < value; }
};

}  // end namespace internal
}  // end namespace Eigen

#endif  // EIGEN_TENSOR_TENSOR_DIMENSION_LIST_H