/// Returns an iterator over (column_name, estimated_size) for each column
Returns an iterator over (column_name, estimated_size) for each column
Returns an iterator over ( column_name estimated_size ) for each column
pub fn column_sizes(&self) -> impl Iterator<Item = (&str, usize)> + '_ {
        self.columns
            .iter()
            .map(|(column_name, c)| (column_name.as_str(), c.size()))
    }
pub fn column_sizes ( & self ) -> impl Iterator < Item = ( & str , usize ) > + ' _ { self . columns . iter ( ) . map ( | ( column_name , c ) | ( column_name . as_str ( ) , c . size ( ) ) ) }
Returns an iterator over (column_name, estimated_size) for each column
Returns an iterator over ( column_name estimated_size ) for each column
&self