Re: [eigen] problem with selfadjointView

[Ben Goodrich <bgokgm@xxxxxxxxxxxxxx>]

On Sun, Aug 22, 2010 at 11:28 AM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
>
>
> 2010/8/22 Ben Goodrich <bgokgm@xxxxxxxxxxxxxx>
>>
>> On Sun, Aug 22, 2010 at 7:39 AM, Jitse Niesen <jitse@xxxxxxxxxxxxxxxxx>
>> wrote:
>> > On Sat, 21 Aug 2010, Ben Goodrich wrote:
>> >
>> >> Thanks for implementing that. Is there something special needed to
>> >> make it work with templates? I would have expected
>> >>
>> >> template <typename Derived>
>> >> void bar(const MatrixBase<Derived> &x, const MatrixBase<Derived> &A,
>> >> MatrixBase<Derived> &z) {
>> >> z = x.transpose() * A.selfadjointView<Lower>() * x;
>> >> }
>> >>
>> >> to work now, but the compiler throws an expected primary-expression
>> >> error.
>> >
>> > Perhaps you need to add the 'template' keyword, as in:
>> >
>> >   z = x.transpose() * A.template selfadjointView<Lower>() * x;
>> >
>> > Warning: I did not try it out.
>> >
>> >
>> > Jitse
>>
>> I had tried that yesterday but forgot to mention it. It doesn't work
>> for me, but maybe the .template() trick should be mentioned somewhere
>> in the documentation?
>
> I confirm what Jitse says, but since it's a general C++ syntax quirk, it's
> hard for us to document it everywhere where needed.
>
> Can you paste the whole compiler error that you're getting?
>
> Benoit

Aha! What Jitse says does, in fact, work for me. I was incorrectly
using template() and g++ was telling me

benchmark.cc:6: error: expected primary-expression before ‘)’ token

which was the same cryptic compiler error that it was giving me when I
was just doing

 z = x.transpose() * A.selfadjointView<Lower>() * x;

so I incorrectly assumed that it wasn't making any difference.

Thanks,
Ben