Export MapKeyIter in public interface

Export the MapKeyIter type as part of the public interface. The type
itself has always been public, it just couldn't be named. Improve
ergonomics and documentation by exporting it properly.

Signed-off-by: Daniel Müller <[email protected]>

Author: d-e-s-o

libbpf-rs/src/lib.rs

@@ -112,6 +112,7 @@ pub use crate::map::Map;
 pub use crate::map::MapFlags;
 pub use crate::map::MapHandle;
 pub use crate::map::MapInfo;
+pub use crate::map::MapKeyIter;
 pub use crate::map::MapType;
 pub use crate::map::OpenMap;
 pub use crate::object::AsRawLibbpf;

libbpf-rs/src/map.rs

@@ -1108,6 +1108,7 @@ impl From<MapType> for u32 {
     }
 }
 
+/// An iterator over the keys of a [`Map`].
 #[derive(Debug)]
 pub struct MapKeyIter<'a> {
     map: &'a MapHandle,