chore: minor improvement for docs

src/adaptors/mod.rs

@@ -992,7 +992,7 @@ fn transpose_result<T, E>(result: Result<Option<T>, E>) -> Option<Result<T, E>>
     }
 }
 
-/// Create a new `FilterOk` iterator.
+/// Create a new `FilterMapOk` iterator.
 pub fn filter_map_ok<I, F, T, U, E>(iter: I, f: F) -> FilterMapOk<I, F>
 where
     I: Iterator<Item = Result<T, E>>,

src/size_hint.rs

@@ -85,6 +85,7 @@ pub fn min(a: SizeHint, b: SizeHint) -> SizeHint {
     (lower, upper)
 }
 
+/// Test multiplication of size hints.
 #[test]
 fn mul_size_hints() {
     assert_eq!(mul((3, Some(4)), (3, Some(4))), (9, Some(16)));

src/tuple_impl.rs

@@ -385,6 +385,7 @@ macro_rules! impl_tuple_collect {
                 count_ident!($($Y)*)
             }
 
+            /// Shift all elements one position to the left and push the new item to the end.
             fn left_shift_push(&mut self, mut item: A) {
                 use std::mem::replace;