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eigen/disabled/class_Eval.cpp
Benoit Jacob e74fbfb2bc - remove Eval/EvalOMP (moving them to a disabled/ subdir in order
to preserve SVN history). They are made useless by the new
  ei_eval_unless_lazy.
- introduce a generic Eval member typedef so one can do e.g.
  T t; U u; Product<T, U>::Eval m; m = t*u;
2008-03-31 17:24:09 +00:00

29 lines
762 B
C++

#include <Eigen/Core>
USING_PART_OF_NAMESPACE_EIGEN
using namespace std;
template<typename Derived>
const Eigen::Eval<Eigen::Transpose<Derived> >
evaluatedTranspose(const MatrixBase<Derived>& m)
{
return m.transpose().eval();
}
int main(int, char**)
{
Matrix2f M = Matrix2f::random();
Matrix2f m;
m = M;
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Now we want to replace m by its own transpose." << endl;
cout << "If we do m = m.transpose(), then m becomes:" << endl;
m = m.transpose();
cout << m << endl << "which is wrong!" << endl;
cout << "Now let us instead do m = evaluatedTranspose(m). Then m becomes" << endl;
m = M;
m = evaluatedTranspose(m);
cout << m << endl << "which is right." << endl;
return 0;
}