Stride.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2010 Benoit Jacob <jacob.benoit.1@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/.

#ifndef EIGEN_STRIDE_H
#define EIGEN_STRIDE_H

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

namespace Eigen {

template <int OuterStrideAtCompileTime_, int InnerStrideAtCompileTime_>
class Stride {
 public:
  typedef Eigen::Index Index;  
  enum { InnerStrideAtCompileTime = InnerStrideAtCompileTime_, OuterStrideAtCompileTime = OuterStrideAtCompileTime_ };

  EIGEN_DEVICE_FUNC Stride() : m_outer(OuterStrideAtCompileTime), m_inner(InnerStrideAtCompileTime) {
    // FIXME: for Eigen 4 we should use DynamicIndex instead of Dynamic.
    // FIXME: for Eigen 4 we should also unify this API with fix<>
    eigen_assert(InnerStrideAtCompileTime != Dynamic && OuterStrideAtCompileTime != Dynamic);
  }

  EIGEN_DEVICE_FUNC Stride(Index outerStride, Index innerStride) : m_outer(outerStride), m_inner(innerStride) {}

  EIGEN_DEVICE_FUNC Stride(const Stride& other) : m_outer(other.outer()), m_inner(other.inner()) {}

  EIGEN_DEVICE_FUNC Stride& operator=(const Stride& other) {
    m_outer.setValue(other.outer());
    m_inner.setValue(other.inner());
    return *this;
  }

  EIGEN_DEVICE_FUNC constexpr Index outer() const { return m_outer.value(); }
  EIGEN_DEVICE_FUNC constexpr Index inner() const { return m_inner.value(); }

 protected:
  internal::variable_if_dynamic<Index, OuterStrideAtCompileTime> m_outer;
  internal::variable_if_dynamic<Index, InnerStrideAtCompileTime> m_inner;
};

template <int Value>
class InnerStride : public Stride<0, Value> {
  typedef Stride<0, Value> Base;

 public:
  EIGEN_DEVICE_FUNC InnerStride() : Base() {}
  EIGEN_DEVICE_FUNC InnerStride(Index v) : Base(0, v) {}  // FIXME making this explicit could break valid code
};

template <int Value>
class OuterStride : public Stride<Value, 0> {
  typedef Stride<Value, 0> Base;

 public:
  EIGEN_DEVICE_FUNC OuterStride() : Base() {}
  EIGEN_DEVICE_FUNC OuterStride(Index v) : Base(v, 0) {}  // FIXME making this explicit could break valid code
};

}  // end namespace Eigen

#endif  // EIGEN_STRIDE_H