Add PointerMutability

Author: dtolnay

src/expr.rs

@@ -1099,6 +1099,17 @@ ast_enum! {
     }
 }
 
+#[cfg(feature = "full")]
+ast_enum! {
+    /// Mutability of a raw pointer (`*const T`, `*mut T`), in which non-mutable
+    /// isn't the implicit default.
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub enum PointerMutability {
+        Const(Token![const]),
+        Mut(Token![mut]),
+    }
+}
+
 #[cfg(feature = "parsing")]
 pub(crate) mod parsing {
     #[cfg(feature = "full")]
@@ -1112,7 +1123,7 @@ pub(crate) mod parsing {
         Arm, ExprArray, ExprAssign, ExprAsync, ExprAwait, ExprBlock, ExprBreak, ExprClosure,
         ExprConst, ExprContinue, ExprForLoop, ExprIf, ExprInfer, ExprLet, ExprLoop, ExprMatch,
         ExprRange, ExprRepeat, ExprReturn, ExprTry, ExprTryBlock, ExprUnsafe, ExprWhile, ExprYield,
-        Label, RangeLimits,
+        Label, PointerMutability, RangeLimits,
     };
     use crate::expr::{
         Expr, ExprBinary, ExprCall, ExprCast, ExprField, ExprGroup, ExprIndex, ExprLit, ExprMacro,
@@ -2969,6 +2980,21 @@ pub(crate) mod parsing {
         }
     }
 
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for PointerMutability {
+        fn parse(input: ParseStream) -> Result<Self> {
+            let lookahead = input.lookahead1();
+            if lookahead.peek(Token![const]) {
+                Ok(PointerMutability::Const(input.parse()?))
+            } else if lookahead.peek(Token![mut]) {
+                Ok(PointerMutability::Mut(input.parse()?))
+            } else {
+                Err(lookahead.error())
+            }
+        }
+    }
+
     fn check_cast(input: ParseStream) -> Result<()> {
         let kind = if input.peek(Token![.]) && !input.peek(Token![..]) {
             if input.peek2(Token![await]) {
@@ -3004,7 +3030,7 @@ pub(crate) mod printing {
         Arm, ExprArray, ExprAssign, ExprAsync, ExprAwait, ExprBlock, ExprBreak, ExprClosure,
         ExprConst, ExprContinue, ExprForLoop, ExprIf, ExprInfer, ExprLet, ExprLoop, ExprMatch,
         ExprRange, ExprRepeat, ExprReturn, ExprTry, ExprTryBlock, ExprUnsafe, ExprWhile, ExprYield,
-        Label, RangeLimits,
+        Label, PointerMutability, RangeLimits,
     };
     use crate::expr::{
         Expr, ExprBinary, ExprCall, ExprCast, ExprField, ExprGroup, ExprIndex, ExprLit, ExprMacro,
@@ -3928,4 +3954,15 @@ pub(crate) mod printing {
             }
         }
     }
+
+    #[cfg(feature = "full")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for PointerMutability {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            match self {
+                PointerMutability::Const(const_token) => const_token.to_tokens(tokens),
+                PointerMutability::Mut(mut_token) => mut_token.to_tokens(tokens),
+            }
+        }
+    }
 }

src/gen/clone.rs

@@ -363,7 +363,7 @@ pub use crate::error::{Error, Result};
 mod expr;
 #[cfg(feature = "full")]
 #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
-pub use crate::expr::{Arm, Label, RangeLimits};
+pub use crate::expr::{Arm, Label, PointerMutability, RangeLimits};
 #[cfg(any(feature = "full", feature = "derive"))]
 #[cfg_attr(docsrs, doc(cfg(any(feature = "full", feature = "derive"))))]
 pub use crate::expr::{