From b0c66adfb1c72d060ec98ebf1004a73b6e4cd559 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Mon, 1 Oct 2018 23:21:37 +0200
Subject: bug #231: initial implementation of STL iterators for dense
 expressions

---
 test/stl_iterators.cpp | 128 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 test/stl_iterators.cpp

(limited to 'test/stl_iterators.cpp')

diff --git a/test/stl_iterators.cpp b/test/stl_iterators.cpp
new file mode 100644
index 000000000..1ed52b354
--- /dev/null
+++ b/test/stl_iterators.cpp
@@ -0,0 +1,128 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2018 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/.
+
+#include "main.h"
+
+template< class Iterator >
+std::reverse_iterator<Iterator>
+make_reverse_iterator( Iterator i )
+{
+  return std::reverse_iterator<Iterator>(i);
+}
+
+template<typename Scalar, int Rows, int Cols>
+void test_range_for_loop(int rows=Rows, int cols=Cols)
+{
+  using std::begin;
+  using std::end;
+
+  typedef Matrix<Scalar,Rows,1> VectorType;
+  typedef Matrix<Scalar,Rows,Cols,ColMajor> ColMatrixType;
+  typedef Matrix<Scalar,Rows,Cols,RowMajor> RowMatrixType;
+  VectorType v = VectorType::Random(rows);
+  ColMatrixType A = ColMatrixType::Random(rows,cols);
+  RowMatrixType B = RowMatrixType::Random(rows,cols);
+  
+  Index i, j;
+  
+#if EIGEN_HAS_CXX11
+  i = 0;
+  for(auto x : v) { VERIFY_IS_EQUAL(x,v[i++]); }
+
+  j = internal::random<Index>(0,A.cols()-1);
+  i = 0;
+  for(auto x : A.col(j)) { VERIFY_IS_EQUAL(x,A(i++,j)); }
+
+  i = 0;
+  for(auto x : (v+A.col(j))) { VERIFY_IS_APPROX(x,v(i)+A(i,j)); ++i; }
+
+  j = 0;
+  i = internal::random<Index>(0,A.rows()-1);
+  for(auto x : A.row(i)) { VERIFY_IS_EQUAL(x,A(i,j++)); }
+
+  i = 0;
+  for(auto x : A.reshaped()) { VERIFY_IS_EQUAL(x,A(i++)); }
+
+  Matrix<Scalar,Dynamic,Dynamic,ColMajor> Bc = B;
+  i = 0;
+  for(auto x : B.reshaped()) { VERIFY_IS_EQUAL(x,Bc(i++)); }
+
+  VectorType w(v.size());
+  i = 0;
+  for(auto& x : w) { x = v(i++); }
+  VERIFY_IS_EQUAL(v,w);
+#endif
+
+  if(rows>=2)
+  {
+    v(1) = v(0)-Scalar(1);
+    VERIFY(!std::is_sorted(begin(v),end(v)));
+  }
+  std::sort(begin(v),end(v));
+  VERIFY(std::is_sorted(begin(v),end(v)));
+  VERIFY(!std::is_sorted(make_reverse_iterator(end(v)),make_reverse_iterator(begin(v))));
+
+  {
+    j = internal::random<Index>(0,A.cols()-1);
+    // std::sort(begin(A.col(j)),end(A.col(j))); // does not compile because this returns const iterators
+    typename ColMatrixType::ColXpr Acol = A.col(j);
+    std::sort(begin(Acol),end(Acol));
+    VERIFY(std::is_sorted(Acol.cbegin(),Acol.cend()));
+
+    // This raises an assert because this creates a pair of iterator referencing two different proxy objects:
+    // std::sort(A.col(j).begin(),A.col(j).end());
+    // VERIFY(std::is_sorted(A.col(j).cbegin(),A.col(j).cend())); // same issue
+  }
+
+  {
+    j = internal::random<Index>(0,A.cols()-1);
+    typename ColMatrixType::ColXpr Acol = A.col(j);
+    std::partial_sum(begin(Acol), end(Acol), begin(v));
+    VERIFY_IS_APPROX(v(seq(1,last)), v(seq(0,last-1))+Acol(seq(1,last)));
+
+    // inplace
+    std::partial_sum(begin(Acol), end(Acol), begin(Acol));
+    VERIFY_IS_APPROX(v, Acol);
+  }
+
+#if EIGEN_HAS_CXX11
+  j = 0;
+  for(auto c : A.allCols()) { VERIFY_IS_APPROX(c.sum(), A.col(j).sum()); ++j; }
+  j = 0;
+  for(auto c : B.allCols()) { VERIFY_IS_APPROX(c.sum(), B.col(j).sum()); ++j; }
+
+  j = 0;
+  for(auto c : B.allCols()) {
+    i = 0;
+    for(auto& x : c) {
+      VERIFY_IS_EQUAL(x, B(i,j));
+      x = A(i,j);
+      ++i;
+    }
+    ++j;
+  }
+  VERIFY_IS_APPROX(A,B);
+  B = Bc; // restore B
+  
+  i = 0;
+  for(auto r : A.allRows()) { VERIFY_IS_APPROX(r.sum(), A.row(i).sum()); ++i; }
+  i = 0;
+  for(auto r : B.allRows()) { VERIFY_IS_APPROX(r.sum(), B.row(i).sum()); ++i; }
+
+#endif
+}
+
+EIGEN_DECLARE_TEST(stl_iterators)
+{
+  for(int i = 0; i < g_repeat; i++) {
+    CALL_SUBTEST_1(( test_range_for_loop<double,2,3>() ));
+    CALL_SUBTEST_1(( test_range_for_loop<float,7,5>() ));
+    CALL_SUBTEST_1(( test_range_for_loop<int,Dynamic,Dynamic>(internal::random<int>(10,200), internal::random<int>(10,200)) ));
+  }
+}
-- 
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