Adding map-inner feature for getting access to map fields

Author: JustForFun88

Cargo.toml

@@ -50,6 +50,7 @@ rustc-dep-of-std = [
     "rustc-internal-api",
 ]
 raw = []
+map-inner = ["raw"]
 
 # Enables usage of `#[inline]` on far more functions than by default in this
 # crate. This may lead to a performance increase but often comes at a compile

src/map.rs

@@ -186,8 +186,15 @@ pub enum DefaultHashBuilder {}
 /// // use the values stored in map
 /// ```
 pub struct HashMap<K, V, S = DefaultHashBuilder, A: Allocator + Clone = Global> {
+    #[cfg(any(feature = "rustc-internal-api", not(feature = "map-inner")))]
     pub(crate) hash_builder: S,
+    #[cfg(any(feature = "rustc-internal-api", not(feature = "map-inner")))]
     pub(crate) table: RawTable<(K, V), A>,
+
+    #[cfg(all(feature = "map-inner", not(feature = "rustc-internal-api")))]
+    pub hash_builder: S,
+    #[cfg(all(feature = "map-inner", not(feature = "rustc-internal-api")))]
+    pub table: RawTable<(K, V), A>,
 }
 
 impl<K: Clone, V: Clone, S: Clone, A: Allocator + Clone> Clone for HashMap<K, V, S, A> {