src/libs/intertrait/cast/rc.rs


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//! 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::rc::Rc;

use error_stack::report;

use crate::libs::intertrait::cast::error::CastError;
use crate::libs::intertrait::{caster, CastFrom};

pub trait CastRc
{
    /// Casts an `Rc` for this trait into that for type `OtherTrait`.
    fn cast<OtherTrait: ?Sized + 'static>(
        self: Rc<Self>,
    ) -> error_stack::Result<Rc<OtherTrait>, CastError>;
}

/// A blanket implementation of `CastRc` for traits extending `CastFrom`.
impl<CastFromSelf: ?Sized + CastFrom> CastRc for CastFromSelf
{
    fn cast<OtherTrait: ?Sized + 'static>(
        self: Rc<Self>,
    ) -> error_stack::Result<Rc<OtherTrait>, CastError>
    {
        match caster::<OtherTrait>((*self).type_id()) {
            Some(caster) => Ok((caster.cast_rc)(self.rc_any())),
            None => Err(report!(CastError).attach_printable(format!(
                "From {} to {}",
                type_name::<CastFromSelf>(),
                type_name::<OtherTrait>()
            ))),
        }
    }
}