pub fn previous_midpoint(&self, index: usize) -> Option<PageId> {
        for &page_id in self.children[..index + 1].iter().rev() {
            if page_id != PageId::max() {
                return Some(page_id);
            }
        }
        None
    }
/// Return the page id of the child for the midpoint at or before `index`.
Return the page id of the child for the midpoint at or before `index`.
Return the page id of the child for the midpoint at or before ` index ` .
pub fn previous_midpoint(&self, index: usize) -> Option<PageId> {
        for &page_id in self.children[..index + 1].iter().rev() {
            if page_id != PageId::max() {
                return Some(page_id);
            }
        }
        None
    }
pub fn previous_midpoint ( & self , index : usize ) -> Option < PageId > { for & page_id in self . children [ .. index + 1 ] . iter ( ) . rev ( ) { if page_id != PageId :: max ( ) { return Some ( page_id ) ; } } None }
Return the page id of the child for the midpoint at or before `index`.
Return the page id of the child for the midpoint at or before ` index ` .
&self
index
usize
&self
index
usize