pub fn stone_at(&self, pos: u64) -> Option<Stone> {
        if pos.count_ones() != 1 {
            None
        } else if self.black_stones & pos > 0 {
            Some(Stone::Black)
        } else if self.white_stones & pos > 0 {
            Some(Stone::White)
        } else {
            None
        }
    }
/// Queries the board in the specified position after a stone.
///
/// If the argument `pos` does not have exactly one bit set, the function
/// will evaluate to None.
///
/// # Examples
/// ```rust
/// use magpie::othello::{OthelloBoard, Stone};
///
/// let board = OthelloBoard::standard();
/// let pos = 0x8000000;
/// assert_eq!(Some(Stone::White), board.stone_at(pos));
///  ```
Queries the board in the specified position after a stone.
If the argument `pos` does not have exactly one bit set, the function
will evaluate to None.
Queries the board in the specified position after a stone . If the argument ` pos ` does not have exactly one bit set the function will evaluate to None .
pub fn stone_at(&self, pos: u64) -> Option<Stone> {
        if pos.count_ones() != 1 {
            None
        } else if self.black_stones & pos > 0 {
            Some(Stone::Black)
        } else if self.white_stones & pos > 0 {
            Some(Stone::White)
        } else {
            None
        }
    }
pub fn stone_at ( & self , pos : u64 ) -> Option < Stone > { if pos . count_ones ( ) != 1 { None } else if self . black_stones & pos > 0 { Some ( Stone :: Black ) } else if self . white_stones & pos > 0 { Some ( Stone :: White ) } else { None } }
Queries the board in the specified position after a stone.
Queries the board in the specified position after a stone .
&self
pos
u64
examples
```rust
use magpie::othello::{OthelloBoard, Stone}.

let board = OthelloBoard::standard();
let pos = 0x8000000;
assert_eq!(Some(Stone::White), board.stone_at(pos));
```
` ` ` rust use magpie :: othello :: { OthelloBoard Stone } . let board = OthelloBoard :: standard () ; let pos = 0x8000000 ; assert_eq! ( Some ( Stone :: White ) board . stone_at ( pos )) ; ` ` `