Fix the doctest in the README.md.

See rust-lang/rust#134221 for more details.

Author: raldone01

trait_cast_rs/README.md

@@ -39,9 +39,7 @@ Note: No modifications on the *target* traits are necessary. Which allows you to
 ## Example
 
 ```rust
-#![feature(
-  ptr_metadata, //
-)]
+#![feature(ptr_metadata, min_specialization)]
 use trait_cast_rs::{
   make_trait_castable, TraitcastableAny, TraitcastableAnyInfra, TraitcastableAnyInfraExt,
 };
@@ -52,7 +50,7 @@ trait Print {
 }
 impl Print for Source {
   fn print(&self) {
-    println!("{}", self.0)
+    println!("{}", self.0);
   }
 }
 

trait_cast_rs/src/test.rs

@@ -1,4 +1,6 @@
-use crate::make_trait_castable_decl;
+use crate::{make_trait_castable_decl, TraitcastableAny, TraitcastableAnyInfra};
+use alloc::boxed::Box;
+use trait_cast_impl_rs::make_trait_castable;
 
 const fn _test_empty_trait_cast_targets() {
   struct Woof {}
@@ -7,3 +9,25 @@ const fn _test_empty_trait_cast_targets() {
     Woof => (),
   }
 }
+
+make_trait_castable_decl! {
+    Source => (Print)
+}
+
+struct Source(i32);
+trait Print {
+  fn print(&self) -> i32;
+}
+impl Print for Source {
+  fn print(&self) -> i32 {
+    self.0
+  }
+}
+
+#[test]
+fn test_trait_castable() {
+  let source = Box::new(Source(5));
+  let castable: Box<dyn TraitcastableAny> = source;
+  let x: &dyn Print = castable.downcast_ref().unwrap();
+  x.print();
+}

trait_cast_rs/src/trait_cast.rs

@@ -148,7 +148,7 @@ pub trait TraitcastableAnyInfraExt<Target: ?Sized + 'static>: Sized {
 #[cfg(feature = "min_specialization")]
 // Safety:
 // Since `traitcast_targets` returns nothing this is always safe.
-// `find_traitcast_target` has the default implementations
+// `find_traitcast_target` has the default implementations.
 unsafe impl<T: 'static> TraitcastableAny for T {
   default fn traitcast_targets(&self) -> &[TraitcastTarget] {
     &[]