Signature Description Parameters
template<typename ... Ts>
DataFrame &
modify_by_idx(DataFrame &rhs, sort_state already_sorted = sort_state::not_sorted);
It iterates over all indices in rhs and modifies all the data columns in self that correspond to the given index value. If not already_sorted, both rhs and self will be sorted by index.
It returns a reference to self
Ts: The list of types for all columns. A type should be specified only once.
already_sorted: If the self and rhs are already sorted by index, this will save the expensive sort operations