allocation free dot product

[David Craven]

seems like a common operation. if Scale had an as_mut method maybe matmul could be reused?

#[inline]
fn dot<T: Entity + SimpleEntity + ComplexField>(a: &Mat<T>, b: &Mat<T>) -> T {
    // TODO: does this allocate?
    (a.transpose() * b)[(0, 0)]
}

[sarah]

you can write a.as_ref().col(0).adjoint() * b.as_ref().col(0), which will give you a T without allocating

though i should make it so you can just write a.col(0) without the intermediate .as_ref()

[David Craven]

thanks!