eigen/test/nestbyvalue.cpp

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2019 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// 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/.

#define TEST_ENABLE_TEMPORARY_TRACKING

#include "main.h"

typedef NestByValue<MatrixXd> CpyMatrixXd;
typedef CwiseBinaryOp<internal::scalar_sum_op<double, double>, const CpyMatrixXd, const CpyMatrixXd> XprType;

XprType get_xpr_with_temps(const MatrixXd& a) {
  MatrixXd t1 = a.rowwise().reverse();
  MatrixXd t2 = a + a;
  return t1.nestByValue() + t2.nestByValue();
}

EIGEN_DECLARE_TEST(nestbyvalue) {
  for (int i = 0; i < g_repeat; i++) {
    Index rows = internal::random<Index>(1, EIGEN_TEST_MAX_SIZE);
    Index cols = internal::random<Index>(1, EIGEN_TEST_MAX_SIZE);
    MatrixXd a = MatrixXd::Random(rows, cols);
    nb_temporaries = 0;
    XprType x = get_xpr_with_temps(a);
    VERIFY_IS_EQUAL(nb_temporaries, 6);
    MatrixXd b = x;
    VERIFY_IS_EQUAL(nb_temporaries, 6 + 1);
    VERIFY_IS_APPROX(b, a.rowwise().reverse().eval() + (a + a).eval());
    // Block expressions work with dense NestByValue.
    VERIFY_IS_APPROX(b, a.nestByValue().rowwise().reverse().eval() + (a.nestByValue() + a.nestByValue()).eval());
  }
}