Accessor of the search-column slot of the gtk-tree-view class.
The gtk-tree-view-search-column slot access function gets the column searched on by the interactive search code.
The (setf gtk-tree-view-search-column) slot access function sets column as the column where the interactive search code should search in for the current model.
If the search column is set, users can use the "start-interactive-search" key binding to bring up search popup. The enable-search property controls whether simply typing text will also start an interactive search.
Note that column refers to a column of the current model. The search column is reset to -1 when the model is changed.