Fix CwiseUnaryView.

test/unaryview.cpp

@@ -0,0 +1,109 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2021 Andrew Johnson <andrew.johnson@arjohnsonau.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/.
+
+#include "main.h"
+
+template <int OuterStride, int InnerStride, typename VectorType>
+void unaryview_stride(const VectorType& m) {
+  typedef typename VectorType::Scalar Scalar;
+  Index rows = m.rows();
+  Index cols = m.cols();
+  VectorType vec = VectorType::Random(rows, cols);
+
+  struct view_op {
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar& operator()(const Scalar& v) const { return v; }
+  };
+
+  CwiseUnaryView<view_op, VectorType, Stride<OuterStride, InnerStride>> vec_view(vec);
+  VERIFY(vec_view.outerStride() == (OuterStride == 0 ? 0 : OuterStride));
+  VERIFY(vec_view.innerStride() == (InnerStride == 0 ? 1 : InnerStride));
+}
+
+void test_mutable_unaryview() {
+  struct Vec3 {
+    double x;
+    double y;
+    double z;
+  };
+
+  Eigen::Vector<Vec3, 3> m;
+  auto x_view = m.unaryViewExpr([](Vec3& v) -> double& { return v.x; });
+  auto y_view = m.unaryViewExpr([](Vec3& v) -> double& { return v.y; });
+  auto z_view = m.unaryViewExpr([](Vec3& v) -> double& { return v.z; });
+
+  x_view.setConstant(1);
+  y_view.setConstant(2);
+  z_view.setConstant(3);
+
+  for (int i = 0; i < m.size(); ++i) {
+    VERIFY_IS_EQUAL(m(i).x, 1);
+    VERIFY_IS_EQUAL(m(i).y, 2);
+    VERIFY_IS_EQUAL(m(i).z, 3);
+  }
+}
+
+void test_unaryview_solve() {
+  // Random upper-triangular system.
+  Eigen::MatrixXd A = Eigen::MatrixXd::Random(5, 5);
+  A.triangularView<Eigen::Lower>().setZero();
+  A.diagonal().setRandom();
+  Eigen::VectorXd b = Eigen::VectorXd::Random(5);
+
+  struct trivial_view_op {
+    double& operator()(double& x) const { return x; }
+    const double& operator()(const double& x) const { return x; }
+  };
+
+  // Non-const view:
+  {
+    auto b_view = b.unaryViewExpr(trivial_view_op());
+    b_view(0) = 1;  // Allows modification.
+    Eigen::VectorXd x = A.triangularView<Eigen::Upper>().solve(b_view);
+    VERIFY_IS_APPROX(A * x, b);
+  }
+
+  // Const view:
+  {
+    const auto b_view = b.unaryViewExpr(trivial_view_op());
+    Eigen::VectorXd x = A.triangularView<Eigen::Upper>().solve(b_view);
+    VERIFY_IS_APPROX(A * x, b);
+  }
+
+  // Non-const view of const matrix:
+  {
+    const Eigen::VectorXd const_b = b;
+    auto b_view = const_b.unaryViewExpr(trivial_view_op());
+    Eigen::VectorXd x = A.triangularView<Eigen::Upper>().solve(b_view);
+    VERIFY_IS_APPROX(A * x, b);
+  }
+
+  // Const view of const matrix:
+  {
+    const Eigen::VectorXd const_b = b;
+    const auto b_view = const_b.unaryViewExpr(trivial_view_op());
+    Eigen::VectorXd x = A.triangularView<Eigen::Upper>().solve(b_view);
+    VERIFY_IS_APPROX(A * x, b);
+  }
+
+  // Eigen::MatrixXd out =
+  //       mat_in.real()
+  //             .triangularView<Eigen::Upper>()
+  //             .solve(mat_in.unaryViewExpr([&](const auto& x){ return std::real(x); }));
+}
+
+EIGEN_DECLARE_TEST(unaryviewstride) {
+  CALL_SUBTEST_1((unaryview_stride<1, 2>(MatrixXf())));
+  CALL_SUBTEST_1((unaryview_stride<0, 0>(MatrixXf())));
+  CALL_SUBTEST_2((unaryview_stride<1, 2>(VectorXf())));
+  CALL_SUBTEST_2((unaryview_stride<0, 0>(VectorXf())));
+  CALL_SUBTEST_3((unaryview_stride<1, 2>(RowVectorXf())));
+  CALL_SUBTEST_3((unaryview_stride<0, 0>(RowVectorXf())));
+  CALL_SUBTEST_4(test_mutable_unaryview());
+  CALL_SUBTEST_4(test_unaryview_solve());
+}