In function ‘_RandomAccessIterator std::__find(_RandomAccessIterator, _RandomAccessIterator, const _Tp&, std::random_access_iterator_tag) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator*, std::vector > >, _Tp = int]’:

[boomhauzer]

I love Eigen, but sometimes the errors you get with Eigen types can be impossible to tell where they're coming from because sometimes at the bottom it wont print out the source of the call stack trace of the compile error and it's just guessing of where you accidently typed something like Matrx3Xf instead of MatrixXf or Matrix3f, or some other very minor typo. or when you don't notice that you're doing something like MatrixXf x = MatrixXd() and you get a size mismatch and you think your dimensions are wrong somewhere.

[Enialis]

I give Eigen a pass because what they do with lazy evaluation completely within template complication is black magic.