If I wish to avoid using template and making a copy (for both mat.col(0) and mat.row(0)), what method should I follow?
The sample code on Ref doc can't be compiled. http://eigen.tuxfamily.org/dox/classEigen_1_1Ref.html

see the question just before yours: viewtopic.php?f=74&t=132136

Code: Select all

Ref<VectorXd,0,InnerStride<> >


As the doc page says, the above code can take both continuous and non-continuous layout.

However, even if the input is contiguously stored in memory, the calculation using this Ref won't be able to exploit vectorization.

So I wish to write two overloads to distinguish them as in http://eigen.tuxfamily.org/dox/classEigen_1_1Ref.html . Unfortunately, the method causes ambiguous calling thus compiler error.