//@run-rustfix #![warn(clippy::box_default)] #[derive(Default)] struct ImplementsDefault; struct OwnDefault; impl OwnDefault { fn default() -> Self { Self } } macro_rules! outer { ($e: expr) => { $e }; } fn main() { let _string: Box = Box::new(Default::default()); let _byte = Box::new(u8::default()); let _vec = Box::new(Vec::::new()); let _impl = Box::new(ImplementsDefault::default()); let _impl2 = Box::new(::default()); let _impl3: Box = Box::new(Default::default()); let _own = Box::new(OwnDefault::default()); // should not lint let _in_macro = outer!(Box::new(String::new())); let _string_default = outer!(Box::new(String::from(""))); let _vec2: Box> = Box::new(vec![]); let _vec3: Box> = Box::new(Vec::from([])); let _vec4: Box<_> = Box::new(Vec::from([false; 0])); let _more = ret_ty_fn(); call_ty_fn(Box::new(u8::default())); issue_10381(); } fn ret_ty_fn() -> Box { Box::new(bool::default()) } #[allow(clippy::boxed_local)] fn call_ty_fn(_b: Box) { issue_9621_dyn_trait(); } use std::io::{Read, Result}; impl Read for ImplementsDefault { fn read(&mut self, _: &mut [u8]) -> Result { Ok(0) } } fn issue_9621_dyn_trait() { let _: Box = Box::new(ImplementsDefault::default()); issue_10089(); } fn issue_10089() { let _closure = || { #[derive(Default)] struct WeirdPathed; let _ = Box::new(WeirdPathed::default()); }; } fn issue_10381() { #[derive(Default)] pub struct Foo {} pub trait Bar {} impl Bar for Foo {} fn maybe_get_bar(i: u32) -> Option> { if i % 2 == 0 { Some(Box::new(Foo::default())) } else { None } } assert!(maybe_get_bar(2).is_some()); }