diff --git a/src/impl_methods.rs b/src/impl_methods.rs index f556f9b4e..8b1ace803 100644 --- a/src/impl_methods.rs +++ b/src/impl_methods.rs @@ -256,6 +256,19 @@ where /// Returns a reference to the first element of the array, or `None` if it /// is empty. + /// + /// # Example + /// + /// ```rust + /// use ndarray::Array3; + /// + /// let mut a = Array3::::zeros([3, 4, 2]); + /// a[[0, 0, 0]] = 42.; + /// assert_eq!(a.first(), Some(&42.)); + /// + /// let b = Array3::::zeros([3, 0, 5]); + /// assert_eq!(b.first(), None); + /// ``` pub fn first(&self) -> Option<&A> where S: Data, @@ -269,6 +282,19 @@ where /// Returns a mutable reference to the first element of the array, or /// `None` if it is empty. + /// + /// # Example + /// + /// ```rust + /// use ndarray::Array3; + /// + /// let mut a = Array3::::zeros([3, 4, 2]); + /// *a.first_mut().unwrap() = 42.; + /// assert_eq!(a[[0, 0, 0]], 42.); + /// + /// let mut b = Array3::::zeros([3, 0, 5]); + /// assert_eq!(b.first_mut(), None); + /// ``` pub fn first_mut(&mut self) -> Option<&mut A> where S: DataMut,