refactor: add back Intertrait tests & Rc support

1 files changed, 30 insertions, 0 deletions

diff --git a/src/libs/intertrait/cast/box.rs b/src/libs/intertrait/cast/box.rs
new file mode 100644
index 0000000..c88fb84
--- /dev/null
+++ b/src/libs/intertrait/cast/box.rs
@@ -0,0 +1,30 @@
+//! Originally from Intertrait by CodeChain
+//!
+//! <https://github.com/CodeChain-io/intertrait>
+//! <https://crates.io/crates/intertrait/0.2.2>
+//!
+//! Licensed under either of
+//!
+//! Apache License, Version 2.0 (LICENSE-APACHE or <http://www.apache.org/licenses/LICENSE-2.0>)
+//! MIT license (LICENSE-MIT or <http://opensource.org/licenses/MIT>)
+//!
+//! at your option.
+use crate::libs::intertrait::{caster, CastFrom};
+
+pub trait CastBox
+{
+    /// Casts a box to this trait into that of type `T`. If fails, returns the receiver.
+    fn cast<T: ?Sized + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>>;
+}
+
+/// A blanket implementation of `CastBox` for traits extending `CastFrom`.
+impl<S: ?Sized + CastFrom> CastBox for S
+{
+    fn cast<T: ?Sized + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>>
+    {
+        match caster::<T>((*self).type_id()) {
+            Some(caster) => Ok((caster.cast_box)(self.box_any())),
+            None => Err(self),
+        }
+    }
+}