PR 572: Add initializer list constructors to Matrix and Array (include unit tests and doc)

- {1,2,3,4,5,...} for fixed-size vectors only
- {{1,2,3},{4,5,6}} for the general cases
- {{1,2,3,4,5,....}} is allowed for both row and column-vector

Eigen/src/Core/Array.h

@@ -178,6 +178,20 @@ class Array
       Base::_check_template_params();
       this->template _init2<T0,T1>(val0, val1);
     }
+
+    #if EIGEN_HAS_CXX11
+    template<typename T>
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Array(const std::initializer_list<T>& list,
+      typename internal::enable_if<internal::is_same<T, Scalar>::value, T>::type* = 0,
+      typename internal::enable_if<RowsAtCompileTime != Dynamic
+                                   && ColsAtCompileTime != Dynamic
+                                   && IsVectorAtCompileTime == 1, T>::type* = 0) : Base(list) {}
+
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Array(const std::initializer_list<std::initializer_list<Scalar> >& list) : Base(list) {}
+    #endif // end EIGEN_HAS_CXX11
+
     #else
     /** \brief Constructs a fixed-sized array initialized with coefficients starting at \a data */
     EIGEN_DEVICE_FUNC explicit Array(const Scalar *data);
@@ -199,7 +213,39 @@ class Array
     Array(Index rows, Index cols);
     /** constructs an initialized 2D vector with given coefficients */
     Array(const Scalar& val0, const Scalar& val1);
-    #endif
+
+    /** \copydoc PlainObjectBase::PlainObjectBase(const std::initializer_list<Scalar>& list) 
+      *
+      * Example: \include Array_initializer_list2_cxx11.cpp
+      * Output: \verbinclude Array_initializer_list2_cxx11.out
+      *
+      * \sa Array::Array(const Scalar& val0, const Scalar& val1)
+      * \sa Array::Array(const Scalar& val0, const Scalar& val1, const Scalar& val2) */
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Array(const std::initializer_list<Scalar>& list);
+
+    /**
+     * \brief Constructs an array and initializes it by elements given by an initializer list of initializer lists \cpp11
+     * 
+     * This constructor distinguishes between the construction of arbitrary array and arrays with one fixed dimension,
+     * 
+     * In the general case, the constructor takes an initializer list, representing the array rows, that contains for
+     * each row an initializer list, representing a single column, containing scalar values. Each of the inner
+     * initializer lists must contain the same number of elements. 
+     * 
+     * In the case of array with one fixed dimension, an initializer list containing just one other initializer list
+     * that contains the array elements can be passed. Therefore \c Array<int,\c Dynamic,\c 1>\c {{1,\c 2,\c 3,\c 4}} is
+     * legal and the more verbose syntax \c Array<int,\c Dynamic,\c 1>\c {{1},\c {2},\c {3},\c {4}} can be avoided.
+     * 
+     * \warning In the case of fixed-sized arrays, the initializer list size must be equal to the array \a rows rows
+     * and \a cols columns.
+     *  
+     * Example: \include Array_initializer_list_cxx11.cpp
+     * Output: \verbinclude Array_initializer_list_cxx11.out
+     */
+    EIGEN_DEVICE_FUNC
+    EIGEN_STRONG_INLINE Array(const std::initializer_list<std::initializer_list<Scalar> >& list);
+    #endif  // end EIGEN_PARSED_BY_DOXYGEN 
 
     /** constructs an initialized 3D vector with given coefficients */
     EIGEN_DEVICE_FUNC

Eigen/src/Core/Matrix.h

@@ -301,6 +301,20 @@ class Matrix
       Base::_check_template_params();
       Base::template _init2<T0,T1>(x, y);
     }
+
+    #if EIGEN_HAS_CXX11
+    template<typename T>
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Matrix(const std::initializer_list<T>& list,
+      typename internal::enable_if<internal::is_same<T, Scalar>::value, T>::type* = 0,
+      typename internal::enable_if<RowsAtCompileTime != Dynamic
+                                   && ColsAtCompileTime != Dynamic
+                                   && IsVectorAtCompileTime == 1, T>::type* = 0) : Base(list) {}
+
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Matrix(const std::initializer_list<std::initializer_list<Scalar>>& list) : Base(list) {}
+    #endif // end EIGEN_HAS_CXX11
+
     #else
     /** \brief Constructs a fixed-sized matrix initialized with coefficients starting at \a data */
     EIGEN_DEVICE_FUNC
@@ -338,7 +352,41 @@ class Matrix
     
     /** \brief Constructs an initialized 2D vector with given coefficients */
     Matrix(const Scalar& x, const Scalar& y);
-    #endif
+
+    /** \copydoc PlainObjectBase::PlainObjectBase(const std::initializer_list<Scalar>& list)
+     *
+     * Example: \include Matrix_initializer_list2_cxx11.cpp
+     * Output: \verbinclude Matrix_initializer_list2_cxx11.out
+     *
+     * \sa Matrix::Matrix(const Scalar& x, const Scalar& y, const Scalar& z)
+     * \sa Matrix::Matrix(const Scalar& x, const Scalar& y, const Scalar& z, const Scalar& w) */
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Matrix(const std::initializer_list<Scalar>& list);
+
+    /**
+     * \brief Constructs a matrix and initializes it by elements given by an initializer list of initializer lists \cpp11
+     * 
+     * This constructor distinguishes between the construction of arbitrary matrices and matrices with one fixed dimension,
+     * i.e., vectors or rowvectors.
+     * 
+     * In the general case, the constructor takes an initializer list, representing the matrix rows, that contains for
+     * each row an initializer list, representing a single column, containing scalar values. Each of the inner
+     * initializer lists must contain the same number of elements. 
+     * 
+     * In the case of matrices with one fixed dimension, an initializer list containing just one other initializer list
+     * that contains the matrix elements can be passed. Therefore \c VectorXi\c {{1,\c 2,\c 3,\c 4}} is legal and the more
+     * verbose syntax \c VectorXi\c {{1},\c {2},\c {3},\c {4}} can be avoided.
+     * 
+     * \warning In the case of fixed-sized matrices, the initializer list size must be equal to the matrix \a rows rows
+     * and \a cols columns.
+     *  
+     * Example: \include Matrix_initializer_list_cxx11.cpp
+     * Output: \verbinclude Matrix_initializer_list_cxx11.out
+     */
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE Matrix(const std::initializer_list<std::initializer_list<Scalar>>& list);
+
+    #endif  // end EIGEN_PARSED_BY_DOXYGEN
 
     /** \brief Constructs an initialized 3D vector with given coefficients */
     EIGEN_DEVICE_FUNC

Eigen/src/Core/PlainObjectBase.h

@@ -526,6 +526,77 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
 //       EIGEN_INITIALIZE_COEFFS_IF_THAT_OPTION_IS_ENABLED
     }
 
+    #ifdef EIGEN_PARSED_BY_DOXYGEN
+    /** 
+     * \brief Construct a vector with fixed number of rows or a rowvector with fixed number of 
+     * columns by passing an initializer list \cpp11
+     *
+     * \only_for_vectors
+     * 
+     * \warning To construct a vector or rowvector of fixed size, the number of values passed through
+     * the initializer list must match the the fixed number of rows in the vector case or
+     * the fixed number of columns in the rowvector case. */
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<Scalar>& list);
+
+    /**
+     * \brief Constructs a Matrix or Array and initializes it by elements given by an initializer list of initializer
+     * lists \cpp11 */
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<std::initializer_list<Scalar>>& list);
+    #else // EIGEN_PARSED_BY_DOXYGEN
+    #if EIGEN_HAS_CXX11
+    template<typename T>
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<T>& list,
+      typename internal::enable_if<internal::is_same<T, Scalar>::value, T>::type* = 0,
+      typename internal::enable_if<RowsAtCompileTime != Dynamic
+                                   && ColsAtCompileTime != Dynamic
+                                   && IsVectorAtCompileTime ==  1, T>::type* = 0)
+      : m_storage()
+    {
+      _check_template_params();
+      EIGEN_STATIC_ASSERT_FIXED_SIZE(PlainObjectBase);
+      resize(list.size());
+      std::copy(list.begin(), list.end(), m_storage.data());
+    }
+
+    EIGEN_DEVICE_FUNC
+    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<std::initializer_list<Scalar>>& list)
+      : m_storage()
+    {
+      _check_template_params();
+
+      size_t list_size = 0;
+      if (list.begin() != list.end()) {
+        list_size = list.begin()->size();
+      }
+
+      // This is to allow syntax like VectorXi {{1, 2, 3, 4}}
+      if (ColsAtCompileTime == 1 && list.size() == 1) {
+        eigen_assert(list_size == static_cast<size_t>(RowsAtCompileTime) || RowsAtCompileTime == Dynamic);
+        resize(list_size, ColsAtCompileTime);
+        std::copy(list.begin()->begin(), list.begin()->end(), m_storage.data());
+      } else {
+        eigen_assert(list.size() == static_cast<size_t>(RowsAtCompileTime) || RowsAtCompileTime == Dynamic);
+        eigen_assert(list_size == static_cast<size_t>(ColsAtCompileTime) || ColsAtCompileTime == Dynamic);
+        resize(list.size(), list_size);
+       
+        Index row_index = 0;
+        for (const std::initializer_list<Scalar>& row : list) {
+          eigen_assert(list_size == row.size());
+          Index col_index = 0;
+          for (const Scalar& e : row) {
+            coeffRef(row_index, col_index) = e;
+            ++col_index;
+          }
+          ++row_index;
+        }
+      }
+    }
+    #endif  // end EIGEN_HAS_CXX11
+    #endif  // end EIGEN_PARSED_BY_DOXYGEN
+
     /** \sa PlainObjectBase::operator=(const EigenBase<OtherDerived>&) */
     template<typename OtherDerived>
     EIGEN_DEVICE_FUNC

doc/TutorialMatrixClass.dox

@@ -101,13 +101,40 @@ Matrix3f a(3,3);
 \endcode
 and is a no-operation.
 
-Finally, we also offer some constructors to initialize the coefficients of small fixed-size vectors up to size 4:
+Additionally, we also offer some constructors to initialize the coefficients of small fixed-size vectors up to size 4:
 \code
 Vector2d a(5.0, 6.0);
 Vector3d b(5.0, 6.0, 7.0);
 Vector4d c(5.0, 6.0, 7.0, 8.0);
 \endcode
 
+If C++11 is enabled, matrices can be constructed and initialized using initializer lists. In the case of fixed-sized vectors
+and rowvectors a simple initializer list can be passed:
+\code
+Vector2i a {1, 2};                  // A vector containing the elements {1, 2}
+Matrix<int, 4, 1> b {1, 2, 3, 4};   // A row-vector containing the elements {1, 2, 3, 4}
+Matrix<int, 1, 4> c {1, 2, 3, 4};   // A vector containing the elements {1, 2, 3, 4}
+\endcode
+
+In the case of fixed or dynamically sized matrices an initializer list containing an initializer list for each row
+can be passed. If the matrix is fixed-sized, the number of elements that are passed must match the dimensions.
+\code
+MatrixXi a {
+      {1, 2},     // first row
+      {3, 4}      // second row
+};
+Matrix<double, 2, 3> b {
+      {2.0, 3.0, 4.0},
+      {5.0, 6.0, 7.0},
+};
+\endcode
+
+In the case of vectors and rowvectors, the following shorthand notation can be used:
+\code
+VectorXd a {{1.5, 2.5, 3.5}};             // A vector with 3 rows
+RowVectorXd b {{1.0, 2.0, 3.0, 4.0}};     // A rowvector with 4 columns
+\endcode
+
 \section TutorialMatrixCoeffAccessors Coefficient accessors
 
 The primary coefficient accessors and mutators in Eigen are the overloaded parenthesis operators.

doc/snippets/Array_initializer_list2_cxx11.cpp

@@ -0,0 +1,3 @@
+Array<int, 1, 6> a {1, 2, 3, 4, 5, 6};
+Array<int, 3, 1> b {1, 2, 3};
+cout << a << "\n\n" << b << endl;

doc/snippets/Array_initializer_list_cxx11.cpp

@@ -0,0 +1,6 @@
+Array<int, 2, 3> a {
+  {1, 2, 3},
+  {3, 4, 5}
+};
+Array<int, Dynamic, 1> v {{1, 2, 3, 4, 5}};
+cout << a << "\n\n" << v << endl;

doc/snippets/Matrix_initializer_list2_cxx11.cpp

@@ -0,0 +1,3 @@
+Matrix<int, 1, 6> a {1, 2, 3, 4, 5, 6};
+Matrix<int, 3, 1> b {1, 2, 3};
+cout << a << "\n\n" << b << endl;

doc/snippets/Matrix_initializer_list_cxx11.cpp

@@ -0,0 +1,6 @@
+Matrix<int, 2, 3> m {
+  {1, 2, 3},
+  {4, 5, 6}
+};
+VectorXi v {{1, 2}};
+cout << m << "\n\n" << v << endl;

failtest/CMakeLists.txt

@@ -63,3 +63,8 @@ ei_add_failtest("bdcsvd_int")
 ei_add_failtest("eigensolver_int")
 ei_add_failtest("eigensolver_cplx")
 
+if(EIGEN_TEST_CXX11)
+  ei_add_failtest("initializer_list_1")
+  ei_add_failtest("initializer_list_2")
+endif()
+

failtest/initializer_list_1.cpp

@@ -0,0 +1,14 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define ROWS Dynamic
+#else
+#define ROWS 3
+#endif
+
+using namespace Eigen;
+
+int main()
+{
+  Matrix<int, ROWS, 1> {1, 2, 3};
+}

failtest/initializer_list_2.cpp

@@ -0,0 +1,16 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define ROWS Dynamic
+#define COLS Dynamic
+#else
+#define ROWS 3
+#define COLS 1
+#endif
+
+using namespace Eigen;
+
+int main()
+{
+  Matrix<int, ROWS, COLS> {1, 2, 3};
+}

test/CMakeLists.txt

@@ -287,6 +287,9 @@ ei_add_test(half_float)
 ei_add_test(array_of_string)
 ei_add_test(num_dimensions)
 ei_add_test(stl_iterators)
+if(EIGEN_TEST_CXX11)
+  ei_add_test(initializer_list_construction)
+endif()
 
 add_executable(bug1213 bug1213.cpp bug1213_main.cpp)
 

test/initializer_list_construction.cpp

@@ -0,0 +1,371 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2019 David Tellenbach <david.tellenbach@tellnotes.org>
+//
+// 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 EIGEN_NO_STATIC_ASSERT
+
+#include "main.h"
+
+template<typename Scalar, bool is_integer = NumTraits<Scalar>::IsInteger>
+struct TestMethodDispatching {
+  static void run() {}
+};
+
+template<typename Scalar>
+struct TestMethodDispatching<Scalar, 1> {
+  static void run()
+  {
+    {
+      Matrix<Scalar, Dynamic, Dynamic> m {3, 4};
+      Array<Scalar, Dynamic, Dynamic> a {3, 4};
+      VERIFY(m.rows() == 3);
+      VERIFY(m.cols() == 4);
+      VERIFY(a.rows() == 3);
+      VERIFY(a.cols() == 4);
+    }
+    {
+      Matrix<Scalar, 1, 2> m {3, 4};
+      Array<Scalar, 1, 2> a {3, 4};
+      VERIFY(m(0) == 3);
+      VERIFY(m(1) == 4);
+      VERIFY(a(0) == 3);
+      VERIFY(a(1) == 4);
+    }
+    {
+      Matrix<Scalar, 2, 1> m {3, 4};
+      Array<Scalar, 2, 1> a {3, 4};
+      VERIFY(m(0) == 3);
+      VERIFY(m(1) == 4);
+      VERIFY(a(0) == 3);
+      VERIFY(a(1) == 4);
+    }
+  }
+};
+
+template<typename Scalar> void singleInitializerListVectorConstruction()
+{
+  Scalar raw[4];
+  for(int k = 0; k < 4; ++k) {
+    raw[k] = internal::random<Scalar>();
+  }
+  {
+    Matrix<Scalar, 1, 4> m { raw[0], raw[1], raw[2], raw[3] };
+    Array<Scalar, 1, 4> a { raw[0], raw[1], raw[2], raw[3] };
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 1, 4>(raw[0], raw[1], raw[2], raw[3])));
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 1, 4>({raw[0], raw[1], raw[2], raw[3]})));
+    VERIFY((a == (Array<Scalar, 1, 4>(raw[0], raw[1], raw[2], raw[3]))).all());
+    VERIFY((a == (Array<Scalar, 1, 4>({raw[0], raw[1], raw[2], raw[3]}))).all());
+  }
+  {
+    Matrix<Scalar, 4, 1> m { raw[0], raw[1], raw[2], raw[3] };
+    Array<Scalar, 4, 1> a { raw[0], raw[1], raw[2], raw[3] };
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 4, 1>(raw[0], raw[1], raw[2], raw[3])));
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 4, 1>({raw[0], raw[1], raw[2], raw[3]})));
+    VERIFY((a == (Array<Scalar, 4, 1>(raw[0], raw[1], raw[2], raw[3]))).all());
+    VERIFY((a == (Array<Scalar, 4, 1>({raw[0], raw[1], raw[2], raw[3]}))).all());
+  }
+}
+
+
+template<typename Scalar> void initializerListVectorConstruction()
+{
+  Scalar raw[4];
+  for(int k = 0; k < 4; ++k) {
+    raw[k] = internal::random<Scalar>();
+  }
+  {
+    Matrix<Scalar, 4, 1> m { {raw[0]}, {raw[1]},{raw[2]},{raw[3]} };
+    Array<Scalar, 4, 1> a { {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} };
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar,4,1>({ {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} })));
+    VERIFY((a == (Array<Scalar,4,1>({ {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} }))).all());
+  }
+  {
+    Matrix<Scalar, 1, 4> m { {raw[0], raw[1], raw[2], raw[3]} };
+    Array<Scalar, 1, 4> a { {raw[0], raw[1], raw[2], raw[3]} };
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k = 0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 1, 4>({{raw[0],raw[1],raw[2],raw[3]}})));
+    VERIFY((a == (Array<Scalar, 1, 4>({{raw[0],raw[1],raw[2],raw[3]}}))).all());
+  }
+  {
+    Matrix<Scalar, 4, Dynamic> m { {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} };
+    Array<Scalar, 4, Dynamic> a { {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} };
+    for(int k=0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k=0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, 4, Dynamic>({ {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} })));
+    VERIFY((a == (Array<Scalar, 4, Dynamic>({ {raw[0]}, {raw[1]}, {raw[2]}, {raw[3]} }))).all());
+  }
+  {
+    Matrix<Scalar, Dynamic, 4> m {{raw[0],raw[1],raw[2],raw[3]}};
+    Array<Scalar, Dynamic, 4> a {{raw[0],raw[1],raw[2],raw[3]}};
+    for(int k=0; k < 4; ++k) {
+      VERIFY(m(k) == raw[k]);
+    }
+    for(int k=0; k < 4; ++k) {
+      VERIFY(a(k) == raw[k]);
+    }
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, Dynamic, 4>({{raw[0],raw[1],raw[2],raw[3]}})));
+    VERIFY((a == (Array<Scalar, Dynamic, 4>({{raw[0],raw[1],raw[2],raw[3]}}))).all());
+  }
+}
+
+template<typename Scalar> void initializerListMatrixConstruction()
+{
+  const Index RowsAtCompileTime = 5;
+  const Index ColsAtCompileTime = 4;
+  const Index SizeAtCompileTime = RowsAtCompileTime * ColsAtCompileTime;
+
+  Scalar raw[SizeAtCompileTime];
+  for (int i = 0; i < SizeAtCompileTime; ++i) {
+    raw[i] = internal::random<Scalar>();
+  }
+  {
+    Matrix<Scalar, Dynamic, Dynamic> m {};
+    VERIFY(m.cols() == 0);
+    VERIFY(m.rows() == 0);
+    VERIFY_IS_EQUAL(m, (Matrix<Scalar, Dynamic, Dynamic>()));
+  }
+  {
+    Matrix<Scalar, 5, 4> m {
+      {raw[0], raw[1], raw[2], raw[3]},
+      {raw[4], raw[5], raw[6], raw[7]},
+      {raw[8], raw[9], raw[10], raw[11]},
+      {raw[12], raw[13], raw[14], raw[15]},
+      {raw[16], raw[17], raw[18], raw[19]}
+    };
+
+    Matrix<Scalar, 5, 4> m2;
+    m2 << raw[0], raw[1], raw[2], raw[3],
+          raw[4], raw[5], raw[6], raw[7],
+          raw[8], raw[9], raw[10], raw[11],
+          raw[12], raw[13], raw[14], raw[15],
+          raw[16], raw[17], raw[18], raw[19];
+
+    int k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        VERIFY(m(i, j) == raw[k]);
+        ++k;
+      }
+    }
+    VERIFY_IS_EQUAL(m, m2);
+  }
+  {
+    Matrix<Scalar, Dynamic, Dynamic> m{
+      {raw[0], raw[1], raw[2], raw[3]},
+      {raw[4], raw[5], raw[6], raw[7]},
+      {raw[8], raw[9], raw[10], raw[11]},
+      {raw[12], raw[13], raw[14], raw[15]},
+      {raw[16], raw[17], raw[18], raw[19]}
+    };
+
+    VERIFY(m.cols() == 4);
+    VERIFY(m.rows() == 5);
+    int k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        VERIFY(m(i, j) == raw[k]);
+        ++k;
+      }
+    }
+
+    Matrix<Scalar, Dynamic, Dynamic> m2(RowsAtCompileTime, ColsAtCompileTime);
+    k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        m2(i, j) = raw[k];
+        ++k;
+      }
+    }
+    VERIFY_IS_EQUAL(m, m2);
+  }
+}
+
+template<typename Scalar> void initializerListArrayConstruction()
+{
+  const Index RowsAtCompileTime = 5;
+  const Index ColsAtCompileTime = 4;
+  const Index SizeAtCompileTime = RowsAtCompileTime * ColsAtCompileTime;
+
+  Scalar raw[SizeAtCompileTime];
+  for (int i = 0; i < SizeAtCompileTime; ++i) {
+    raw[i] = internal::random<Scalar>();
+  }
+  {
+    Array<Scalar, Dynamic, Dynamic> a {};
+    VERIFY(a.cols() == 0);
+    VERIFY(a.rows() == 0);
+  }
+  {
+    Array<Scalar, 5, 4> m {
+      {raw[0], raw[1], raw[2], raw[3]},
+      {raw[4], raw[5], raw[6], raw[7]},
+      {raw[8], raw[9], raw[10], raw[11]},
+      {raw[12], raw[13], raw[14], raw[15]},
+      {raw[16], raw[17], raw[18], raw[19]}
+    };
+
+    Array<Scalar, 5, 4> m2;
+    m2 << raw[0], raw[1], raw[2], raw[3],
+          raw[4], raw[5], raw[6], raw[7],
+          raw[8], raw[9], raw[10], raw[11],
+          raw[12], raw[13], raw[14], raw[15],
+          raw[16], raw[17], raw[18], raw[19];
+
+    int k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        VERIFY(m(i, j) == raw[k]);
+        ++k;
+      }
+    }
+    VERIFY_IS_APPROX(m, m2);
+  }
+  {
+    Array<Scalar, Dynamic, Dynamic> m {
+      {raw[0], raw[1], raw[2], raw[3]},
+      {raw[4], raw[5], raw[6], raw[7]},
+      {raw[8], raw[9], raw[10], raw[11]},
+      {raw[12], raw[13], raw[14], raw[15]},
+      {raw[16], raw[17], raw[18], raw[19]}
+    };
+
+    VERIFY(m.cols() == 4);
+    VERIFY(m.rows() == 5);
+    int k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        VERIFY(m(i, j) == raw[k]);
+        ++k;
+      }
+    }
+
+    Array<Scalar, Dynamic, Dynamic> m2(RowsAtCompileTime, ColsAtCompileTime);
+    k = 0;
+    for(int i = 0; i < RowsAtCompileTime; ++i) {
+      for (int j = 0; j < ColsAtCompileTime; ++j) {
+        m2(i, j) = raw[k];
+        ++k;
+      }
+    }
+    VERIFY_IS_APPROX(m, m2);
+  }
+}
+
+template<typename Scalar> void dynamicVectorConstruction()
+{
+  const Index size = 4;
+  Scalar raw[size];
+  for (int i = 0; i < size; ++i) {
+    raw[i] = internal::random<Scalar>();
+  }
+
+  typedef Matrix<Scalar, Dynamic, 1>  VectorX;
+
+  {
+    VectorX v {{raw[0], raw[1], raw[2], raw[3]}};
+    for (int i = 0; i < size; ++i) {
+      VERIFY(v(i) == raw[i]);
+    }
+    VERIFY(v.rows() == size);
+    VERIFY(v.cols() == 1);
+    VERIFY_IS_EQUAL(v, (VectorX {{raw[0], raw[1], raw[2], raw[3]}}));
+  }
+
+  {
+    VERIFY_RAISES_ASSERT((VectorX {raw[0], raw[1], raw[2], raw[3]}));
+  }
+  {
+    VERIFY_RAISES_ASSERT((VectorX  {
+      {raw[0], raw[1], raw[2], raw[3]},
+      {raw[0], raw[1], raw[2], raw[3]},
+    }));
+  }
+}
+
+EIGEN_DECLARE_TEST(initializer_list_construction)
+{
+  CALL_SUBTEST_1(initializerListVectorConstruction<unsigned char>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<float>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<double>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<int>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<long int>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<std::ptrdiff_t>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<std::complex<int>>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<std::complex<double>>());
+  CALL_SUBTEST_1(initializerListVectorConstruction<std::complex<float>>());
+
+  CALL_SUBTEST_2(initializerListMatrixConstruction<unsigned char>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<float>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<double>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<int>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<long int>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<std::ptrdiff_t>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<std::complex<int>>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<std::complex<double>>());
+  CALL_SUBTEST_2(initializerListMatrixConstruction<std::complex<float>>());
+
+  CALL_SUBTEST_3(initializerListArrayConstruction<unsigned char>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<float>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<double>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<int>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<long int>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<std::ptrdiff_t>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<std::complex<int>>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<std::complex<double>>());
+  CALL_SUBTEST_3(initializerListArrayConstruction<std::complex<float>>());
+
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<unsigned char>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<float>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<double>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<int>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<long int>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<std::ptrdiff_t>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<std::complex<int>>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<std::complex<double>>());
+  CALL_SUBTEST_4(singleInitializerListVectorConstruction<std::complex<float>>());
+
+  CALL_SUBTEST_5(TestMethodDispatching<int>::run());
+  CALL_SUBTEST_5(TestMethodDispatching<long int>::run());
+
+  CALL_SUBTEST_6(dynamicVectorConstruction<unsigned char>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<float>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<double>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<int>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<long int>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<std::ptrdiff_t>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<std::complex<int>>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<std::complex<double>>());
+  CALL_SUBTEST_6(dynamicVectorConstruction<std::complex<float>>());
+}