Re: [eigen] unpleasant surprise mit math functions

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 22.09.2012 22:21, Gael Guennebaud wrote:
> there is indeed something very strange happening. I've no idea why
> sin(t) with t a VectorXd does compile. It seems it manages to directly
> found Eigen::internal::sin even though VectorXd is defined in the
> Eigen namespace, not Eigen::internal. [...]


I guess the reason is that Eigen::Matrix has some base classes in 
Eigen::internal. I modified your example accordingly:

namespace A {
  namespace internal {
    template<typename T> T bar(const T& x) { return x; }

    struct Base {};

  }

  struct Matrix : public internal::Base { float x; };
}

int main()
{
  A::Matrix m;
  bar(m); // does compile!
}
// EOE


Christoph




--
----------------------------------------------
Dipl.-Inf. Christoph Hertzberg
Cartesium 0.049
Universität Bremen
Enrique-Schmidt-Straße 5
28359 Bremen

Tel: +49 (421) 218-64252
----------------------------------------------