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

6 files changed, 46 insertions, 1 deletions

diff --git a/doc/TutorialMatrixClass.dox b/doc/TutorialMatrixClass.dox
index 7ea0cd789..fc0ce5b1e 100644
--- a/doc/TutorialMatrixClass.dox
+++ b/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.
diff --git a/doc/snippets/Array_initializer_list2_cxx11.cpp b/doc/snippets/Array_initializer_list2_cxx11.cpp
new file mode 100644
index 000000000..20e74546a
--- /dev/null
+++ b/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;
\ No newline at end of file
diff --git a/doc/snippets/Array_initializer_list_cxx11.cpp b/doc/snippets/Array_initializer_list_cxx11.cpp
new file mode 100644
index 000000000..d2f46e268
--- /dev/null
+++ b/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;
\ No newline at end of file
diff --git a/doc/snippets/Matrix_initializer_list2_cxx11.cpp b/doc/snippets/Matrix_initializer_list2_cxx11.cpp
new file mode 100644
index 000000000..2fde52b8d
--- /dev/null
+++ b/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;
\ No newline at end of file
diff --git a/doc/snippets/Matrix_initializer_list_cxx11.cpp b/doc/snippets/Matrix_initializer_list_cxx11.cpp
new file mode 100644
index 000000000..d68787ab6
--- /dev/null
+++ b/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;
\ No newline at end of file
diff --git a/doc/snippets/Tutorial_std_sort_rows.cpp b/doc/snippets/Tutorial_std_sort_rows_cxx11.cpp
index fdd850d13..fdd850d13 100644
--- a/doc/snippets/Tutorial_std_sort_rows.cpp
+++ b/doc/snippets/Tutorial_std_sort_rows_cxx11.cpp