add EIGEN_NO_AUTOMATIC_RESIZING

if defined, already initialized matrices won't be automatically resized in assignments
uninitialized matrices may still be initialized

1 files changed, 6 insertions, 0 deletions

diff --git a/Eigen/src/Core/Matrix.h b/Eigen/src/Core/Matrix.h
index 482afe890..f62037709 100644
--- a/Eigen/src/Core/Matrix.h
+++ b/Eigen/src/Core/Matrix.h
@@ -463,6 +463,12 @@ class Matrix
     template<typename OtherDerived>
     EIGEN_STRONG_INLINE void _resize_to_match(const MatrixBase<OtherDerived>& other)
     {
+      #ifdef EIGEN_NO_AUTOMATIC_RESIZING
+      ei_assert((this->size()==0 || (IsVectorAtCompileTime ? (this->size() == other.size())
+                 : (rows() == other.rows() && cols() == other.cols())))
+        && "Size mismatch. Automatic resizing is disabled because EIGEN_NO_AUTOMATIC_RESIZING is defined");
+      #endif
+
       if(RowsAtCompileTime == 1)
       {
         ei_assert(other.isVector());