Re: [eigen] clang-3.1 issue

[Benjamin Schindler <bschindler@xxxxxxxxxxx>]

After experimenting a little bit more, I was convinced and filed a bug:

http://llvm.org/bugs/show_bug.cgi?id=13103

Cheers
Benjamin

On 13.06.2012 20:27, Gael Guennebaud wrote:
> Indeed, that looks like a clang bug. I've no idea how to workaround it.
>
> gael
>
> On Wed, Jun 13, 2012 at 1:21 PM, Benjamin Schindler
> <bschindler@xxxxxxxxxxx>  wrote:
> > Hi
> >
> > I just stumbled over this issue, may be you have some input on it, but
> > I'm really thinking I have found a clang bug. Consider the attached code
> > (I used latest tip of Eigen). It fails to compile with
> >
> > test.cpp:11:18: error: use of overloaded operator '=' is ambiguous (with
> > operand types 'typename FixedSegmentReturnType<3>::Type' (aka
> > 'VectorBlock<Eigen::Matrix<float, 4, 1, 0, 4, 1>, 3>') and 'const
> > ConstantReturnType' (aka 'const
> >       CwiseNullaryOp<internal::scalar_constant_op<Scalar>,
> > Eigen::Matrix<float, 3, 1, 0, 3, 1>  >'))
> >         input.head<3>() = Vector3f::Zero();
> >         ~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~
> > test.cpp:17:2: note: in instantiation of function template
> > specialization 'myFunction<float>' requested here
> >         myFunction<float>();
> >         ^
> > /local/bschindler/projects/eigen/Eigen/src/Core/MatrixBase.h:169:14:
> > note: candidate function [with OtherDerived =
> > Eigen::CwiseNullaryOp<Eigen::internal::scalar_constant_op<float>,
> > Eigen::Matrix<float, 3, 1, 0, 3, 1>  >]
> >     Derived&  operator=(const DenseBase<OtherDerived>&  other);
> >              ^
> > /local/bschindler/projects/eigen/Eigen/src/Core/MatrixBase.h:172:14:
> > note: candidate function [with OtherDerived =
> > Eigen::CwiseNullaryOp<Eigen::internal::scalar_constant_op<float>,
> > Eigen::Matrix<float, 3, 1, 0, 3, 1>  >]
> >     Derived&  operator=(const EigenBase<OtherDerived>&  other);
> >
> >
> > Now, If I move lines 10 and 11 into the main function it compiles.
> > clang bug?
> >
> > Cheers
> > Benjamin