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eq_trait_object

tract_data::dyn_eq

Macro eq_trait_object 

Source 
macro_rules! eq_trait_object {
    ($trait:ident) => { ... };
}
Expand description

Implement PartialEq and Eq for the objects of a trait having DynEq as a supertrait, in all four Send/Sync combinations.

Takes a bare trait name: a generic trait would need the argument list threaded through, and tract has none needing this.

use tract_data::dyn_eq::DynEq;

trait Weigh: DynEq {}
tract_data::eq_trait_object!(Weigh);

impl Weigh for u8 {}
impl Weigh for u16 {}

let five: &dyn Weigh = &5u8;
assert!(five == &5u8 as &dyn Weigh);
assert!(five != &6u8 as &dyn Weigh);
// same value, other type: not equal
assert!(five != &5u16 as &dyn Weigh);