#![allow(clippy::blacklisted_name, clippy::redundant_clone, clippy::trivially_copy_pass_by_ref)] #[cfg(feature = "use_core")] extern crate core; #[macro_use] extern crate derivative; #[derive(Debug, Derivative, PartialEq)] #[derivative(Clone)] struct Foo { foo: u8, #[derivative(Clone(clone_with="seventh"))] bar: u8, } fn seventh(a: &u8) -> u8 { a/7 } #[derive(Debug, PartialEq)] struct EvilCloneFrom(u8); impl Clone for EvilCloneFrom { fn clone(&self) -> Self { EvilCloneFrom(self.0) } fn clone_from(&mut self, _: &Self) { self.0 = 42; } } #[derive(Derivative)] #[derivative(Clone(clone_from="true"))] struct StructWithCloneFrom(EvilCloneFrom); #[derive(Debug, Derivative, PartialEq)] #[derivative(Clone(clone_from="true"))] enum EnumWithCloneFrom { Evil(EvilCloneFrom), Good(u32), None } #[test] fn main() { let foo = Foo { foo: 31, bar: 42 }; assert_eq!(Foo { foo: 31, bar: 6 }, foo.clone()); let mut foo = StructWithCloneFrom(EvilCloneFrom(27)); foo.clone_from(&StructWithCloneFrom(EvilCloneFrom(0))); assert_eq!((foo.0).0, 42); let mut foo = EnumWithCloneFrom::Evil(EvilCloneFrom(27)); foo.clone_from(&EnumWithCloneFrom::Evil(EvilCloneFrom(0))); assert_eq!(foo, EnumWithCloneFrom::Evil(EvilCloneFrom(42))); let mut foo = EnumWithCloneFrom::Evil(EvilCloneFrom(27)); foo.clone_from(&EnumWithCloneFrom::None); assert_eq!(foo, EnumWithCloneFrom::None); let mut foo = EnumWithCloneFrom::Good(27); foo.clone_from(&EnumWithCloneFrom::None); assert_eq!(foo, EnumWithCloneFrom::None); }