This patch introduces scalar functions `similarity_cosine()`,
`similarity_euclidean()`, and `similarity_dot_product()`
which should return a float - similarity of the given vectors
calculated according to the function's similarity metric.
The argument types of this function are retrieved with
the `retrieve_vector_arg_types`, but shall be assignable to
`vector<float, N>` where `N` is the same for both arguments.
This patch introduces a dimensionality check during the execusion
of those functions.
5b2b8d596a