Allow .conservativeResize(rows,cols) on vectors

2 files changed, 36 insertions, 11 deletions

diff --git a/Eigen/src/Core/PlainObjectBase.h b/Eigen/src/Core/PlainObjectBase.h
index e9aa3a88c..1a4c19233 100644
--- a/Eigen/src/Core/PlainObjectBase.h
+++ b/Eigen/src/Core/PlainObjectBase.h
@@ -47,7 +47,10 @@ template<> struct check_rows_cols_for_overflow<Dynamic> {
   }
 };
 
-template <typename Derived, typename OtherDerived = Derived, bool IsVector = bool(Derived::IsVectorAtCompileTime)> struct conservative_resize_like_impl;
+template <typename Derived,
+          typename OtherDerived = Derived,
+          bool IsVector = bool(Derived::IsVectorAtCompileTime) && bool(OtherDerived::IsVectorAtCompileTime)>
+struct conservative_resize_like_impl;
 
 template<typename MatrixTypeA, typename MatrixTypeB, bool SwapPointers> struct matrix_swap_impl;
 
@@ -682,8 +685,10 @@ private:
     enum { ThisConstantIsPrivateInPlainObjectBase };
 };
 
+namespace internal {
+
 template <typename Derived, typename OtherDerived, bool IsVector>
-struct internal::conservative_resize_like_impl
+struct conservative_resize_like_impl
 {
   typedef typename Derived::Index Index;
   static void run(DenseBase<Derived>& _this, Index rows, Index cols)
@@ -743,11 +748,14 @@ struct internal::conservative_resize_like_impl
   }
 };
 
-namespace internal {
-
+// Here, the specialization for vectors inherits from the general matrix case
+// to allow calling .conservativeResize(rows,cols) on vectors.
 template <typename Derived, typename OtherDerived>
 struct conservative_resize_like_impl<Derived,OtherDerived,true>
+  : conservative_resize_like_impl<Derived,OtherDerived,false>
 {
+  using conservative_resize_like_impl<Derived,OtherDerived,false>::run;
+  
   typedef typename Derived::Index Index;
   static void run(DenseBase<Derived>& _this, Index size)
   {
diff --git a/test/conservative_resize.cpp b/test/conservative_resize.cpp
index 2d1ab3f03..498421b4c 100644
--- a/test/conservative_resize.cpp
+++ b/test/conservative_resize.cpp
@@ -60,34 +60,51 @@ void run_matrix_tests()
 template <typename Scalar>
 void run_vector_tests()
 {
-  typedef Matrix<Scalar, 1, Eigen::Dynamic> MatrixType;
+  typedef Matrix<Scalar, 1, Eigen::Dynamic> VectorType;
 
-  MatrixType m, n;
+  VectorType m, n;
 
   // boundary cases ...
-  m = n = MatrixType::Random(50);
+  m = n = VectorType::Random(50);
   m.conservativeResize(1);
   VERIFY_IS_APPROX(m, n.segment(0,1));
 
-  m = n = MatrixType::Random(50);
+  m = n = VectorType::Random(50);
   m.conservativeResize(50);
   VERIFY_IS_APPROX(m, n.segment(0,50));
+  
+  m = n = VectorType::Random(50);
+  m.conservativeResize(m.rows(),1);
+  VERIFY_IS_APPROX(m, n.segment(0,1));
+
+  m = n = VectorType::Random(50);
+  m.conservativeResize(m.rows(),50);
+  VERIFY_IS_APPROX(m, n.segment(0,50));
 
   // random shrinking ...
   for (int i=0; i<50; ++i)
   {
     const int size = internal::random<int>(1,50);
-    m = n = MatrixType::Random(50);
+    m = n = VectorType::Random(50);
     m.conservativeResize(size);
     VERIFY_IS_APPROX(m, n.segment(0,size));
+    
+    m = n = VectorType::Random(50);
+    m.conservativeResize(m.rows(), size);
+    VERIFY_IS_APPROX(m, n.segment(0,size));
   }
 
   // random growing with zeroing ...
   for (int i=0; i<50; ++i)
   {
     const int size = internal::random<int>(50,100);
-    m = n = MatrixType::Random(50);
-    m.conservativeResizeLike(MatrixType::Zero(size));
+    m = n = VectorType::Random(50);
+    m.conservativeResizeLike(VectorType::Zero(size));
+    VERIFY_IS_APPROX(m.segment(0,50), n);
+    VERIFY( size<=50 || m.segment(50,size-50).sum() == Scalar(0) );
+    
+    m = n = VectorType::Random(50);
+    m.conservativeResizeLike(Matrix<Scalar,Dynamic,Dynamic>::Zero(1,size));
     VERIFY_IS_APPROX(m.segment(0,50), n);
     VERIFY( size<=50 || m.segment(50,size-50).sum() == Scalar(0) );
   }