use std::error::Error; use validit::Valid; use validit::Validate; struct Foo(u64); impl Validate for Foo { fn validate(&self) -> Result<(), Box> { validit::less!(self.0, 10); Ok(()) } } #[test] fn test_valid() { let _a = Valid::new(Foo(1)).0; let res = std::panic::catch_unwind(|| { let _a = Valid::new(Foo(10)).0; }); assert!(res.is_err()); }