change example of array_from_fn to match suggestion

library/core/src/array/mod.rs

@@ -38,15 +38,15 @@ pub use iter::IntoIter;
 /// // equal lengths can be compared, so the const generic parameter `N` is
 /// // inferred to be 5, thus creating array of 5 elements.
 ///
-/// let array: [_; 5] = core::array::from_fn(|i| i);
+/// let array = core::array::from_fn(|i| i);
 /// // indexes are:    0  1  2  3  4
 /// assert_eq!(array, [0, 1, 2, 3, 4]);
 ///
-/// let array2: [_; 8] = core::array::from_fn(|i| i * 2);
+/// let array2: [usize; 8] = core::array::from_fn(|i| i * 2);
 /// // indexes are:     0  1  2  3  4  5   6   7
 /// assert_eq!(array2, [0, 2, 4, 6, 8, 10, 12, 14]);
 ///
-/// let bool_arr: [bool; 5] = core::array::from_fn(|i| i % 2 == 0);
+/// let bool_arr = core::array::from_fn::<_, 5, _>(|i| i % 2 == 0);
 /// // indexes are:       0     1      2     3      4
 /// assert_eq!(bool_arr, [true, false, true, false, true]);
 /// ```