Signature Description Parameters

std::size_t
append_index(const IndexType &val);
        
It appends val to the end of the index column. Returns number of items loaded
Returns number of items loaded
val: Single index value

template<typename ITR>
std::size_t
append_index(Index2D range);
        
It appends the range begin to end to the end of the index column
Returns number of items loaded
ITR: Type of the iterator
range: The begin and end iterators for data
C++ DataFrame