Hi all,

compiling the code listed below fails with the following error:

Code: Select all

test.cpp: In function ‘void something()’:
test.cpp:16: error: expected primary-expression before ‘double’
test.cpp:16: error: expected ‘;’ before ‘double’

The commented out variant works fine. Any ideas what is wrong here?
Btw. this happens with GCC 4.3, 4.4 and with Eigen 2 and 3.

Code: Select all

#include <Eigen/Core>
#include <iostream>

struct X {
   enum {
      DIM = 3
   };
};

template <class T>
void something() {
   Eigen::Matrix<int,T::DIM,T::DIM> m;
   //Eigen::Matrix<int,3,3> m;

   m << 1,2,3,4,5,6,7,8,9;
   std::cout << m.cast<double>();
}

int main() {
   something<X>();

   return 0;
}

Best regards, Adam

You have to write "m.template cast<double>()". This is a rather obscure C++ feature; see http://eigen.tuxfamily.org/dox-devel/To ... yword.html for some explanation.