NestByValue.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2006-2008 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/.
// SPDX-License-Identifier: MPL-2.0
 
#ifndef EIGEN_NESTBYVALUE_H
#define EIGEN_NESTBYVALUE_H
 
// IWYU pragma: private
#include "./InternalHeaderCheck.h"
 
namespace Eigen {
 
namespace internal {
template <typename ExpressionType>
struct traits<NestByValue<ExpressionType> > : public traits<ExpressionType> {
  enum { Flags = traits<ExpressionType>::Flags & ~NestByRefBit };
};
}  // namespace internal

template <typename ExpressionType>
class NestByValue : public internal::dense_xpr_base<NestByValue<ExpressionType> >::type {
 public:
  using Base = typename internal::dense_xpr_base<NestByValue>::type;
  static constexpr bool HasDirectAccess = internal::has_direct_access<ExpressionType>::value;
 
  EIGEN_DENSE_PUBLIC_INTERFACE(NestByValue)
 
  EIGEN_DEVICE_FUNC constexpr explicit inline NestByValue(const ExpressionType& matrix) : m_expression(matrix) {}
 
  EIGEN_DEVICE_FUNC constexpr Index rows() const noexcept { return m_expression.rows(); }
  EIGEN_DEVICE_FUNC constexpr Index cols() const noexcept { return m_expression.cols(); }
 
  EIGEN_DEVICE_FUNC constexpr operator const ExpressionType&() const { return m_expression; }
 
  EIGEN_DEVICE_FUNC constexpr const ExpressionType& nestedExpression() const { return m_expression; }
 
  EIGEN_DEVICE_FUNC constexpr std::enable_if_t<HasDirectAccess, const Scalar*> data() const {
    return m_expression.data();
  }
 
  EIGEN_DEVICE_FUNC constexpr std::enable_if_t<HasDirectAccess, Index> innerStride() const {
    return m_expression.innerStride();
  }
 
  EIGEN_DEVICE_FUNC constexpr std::enable_if_t<HasDirectAccess, Index> outerStride() const {
    return m_expression.outerStride();
  }
 
 protected:
  const ExpressionType m_expression;
};

template <typename Derived>
EIGEN_DEVICE_FUNC constexpr inline const NestByValue<Derived> DenseBase<Derived>::nestByValue() const {
  return NestByValue<Derived>(derived());
}
 
namespace internal {
 
// Evaluator of NestByValue<> -> forwards to the evaluator of the nested expression
template <typename ArgType>
struct evaluator<NestByValue<ArgType> > : public evaluator<ArgType> {
  using Base = evaluator<ArgType>;
 
  EIGEN_DEVICE_FUNC constexpr explicit evaluator(const NestByValue<ArgType>& xpr) : Base(xpr.nestedExpression()) {}
};
}  // namespace internal
 
}  // end namespace Eigen
 
#endif  // EIGEN_NESTBYVALUE_H