aboutsummaryrefslogtreecommitdiff
path: root/src/private/cast/arc.rs
diff options
context:
space:
mode:
Diffstat (limited to 'src/private/cast/arc.rs')
-rw-r--r--src/private/cast/arc.rs93
1 files changed, 93 insertions, 0 deletions
diff --git a/src/private/cast/arc.rs b/src/private/cast/arc.rs
new file mode 100644
index 0000000..7ea8b49
--- /dev/null
+++ b/src/private/cast/arc.rs
@@ -0,0 +1,93 @@
+//! 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 std::any::type_name;
+use std::sync::Arc;
+
+use crate::private::cast::error::CastError;
+use crate::private::cast::{get_caster, CastFromSync};
+
+pub trait CastArc
+{
+ /// Casts an `Arc` with `Self` into an `Arc` with `Dest`.
+ fn cast<Dest: ?Sized + 'static>(self: Arc<Self>) -> Result<Arc<Dest>, CastError>;
+}
+
+/// A blanket implementation of `CastArc` for traits extending `CastFrom`, `Sync`, and
+/// `Send`.
+impl<CastFromSelf: ?Sized + CastFromSync> CastArc for CastFromSelf
+{
+ fn cast<Dest: ?Sized + 'static>(self: Arc<Self>) -> Result<Arc<Dest>, CastError>
+ {
+ let caster =
+ get_caster::<Dest>((*self).type_id()).map_err(CastError::GetCasterFailed)?;
+
+ let cast_arc = caster
+ .opt_cast_arc
+ .ok_or(CastError::NotArcCastable(type_name::<Dest>()))?;
+
+ cast_arc(self.arc_any()).map_err(|err| CastError::CastFailed {
+ source: err,
+ from: type_name::<Self>(),
+ to: type_name::<Dest>(),
+ })
+ }
+}
+
+#[cfg(test)]
+mod tests
+{
+ use std::any::Any;
+ use std::fmt::{Debug, Display};
+ use std::sync::Arc;
+
+ use super::*;
+ use crate::test_utils::subjects;
+
+ #[test]
+ fn can_cast_arc()
+ {
+ let concrete_ninja = Arc::new(subjects::Ninja);
+
+ let abstract_ninja: Arc<dyn subjects::INinja> = concrete_ninja;
+
+ let debug_ninja_result = abstract_ninja.cast::<dyn Debug>();
+
+ assert!(debug_ninja_result.is_ok());
+ }
+
+ #[test]
+ fn cannot_cast_arc_wrong()
+ {
+ let concrete_ninja = Arc::new(subjects::Ninja);
+
+ let abstract_ninja: Arc<dyn subjects::INinja> = concrete_ninja;
+
+ let display_ninja_result = abstract_ninja.cast::<dyn Display>();
+
+ assert!(matches!(
+ display_ninja_result,
+ Err(CastError::GetCasterFailed(_))
+ ));
+ }
+
+ #[test]
+ fn can_cast_arc_from_any()
+ {
+ let concrete_ninja = Arc::new(subjects::Ninja);
+
+ let any_ninja: Arc<dyn Any + Send + Sync> = concrete_ninja;
+
+ let debug_ninja_result = any_ninja.cast::<dyn Debug>();
+
+ assert!(debug_ninja_result.is_ok());
+ }
+}