1 #[cfg(feature = "use_core")] 2 extern crate core; 3 4 #[macro_use] 5 extern crate derivative; 6 7 trait Foo {} 8 fmt<T>(_: &T, _: &mut std::fmt::Formatter) -> std::fmt::Result9fn fmt<T>(_: &T, _: &mut std::fmt::Formatter) -> std::fmt::Result { 10 unimplemented!() 11 } 12 13 #[derive(Debug)] 14 struct Qux<'a, T: Foo>(&'a T); 15 16 #[derive(Derivative)] 17 #[derivative(Debug)] 18 struct _Bar<'a, T: Foo>(#[derivative(Debug(format_with="fmt"))] Qux<'a, T>); 19 main()20fn main() { 21 }