Re: [eigen] Ref<> Problem

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 04.12.2014 00:14, Gabriel wrote:
> How can I avoid such errors, and whats the correct way of storing a
> reference to a Matrix  in a class?

You must avoid that a temporary is constructed which runs out of scope 
after being assigned to r:

  struct A{
    // constructor does not generate a temporary:
    template<class Derived>
    A(const Eigen::MatrixBase<Derived> & in) : r(in) {}
    // initializing r might create a temporary but that is stored in r

    Eigen::Ref<const Eigen::MatrixXd> r;
  };

Be aware that strange things might happen, when you try to copy-assign 
elements of type A.


Christoph

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Dipl.-Inf., Dipl.-Math. Christoph Hertzberg
Cartesium 0.049
Universität Bremen
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