93 lines
2.3 KiB
Rust
93 lines
2.3 KiB
Rust
#![warn(clippy::box_default)]
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#![allow(clippy::default_constructed_unit_structs)]
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#[derive(Default)]
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struct ImplementsDefault;
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struct OwnDefault;
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impl OwnDefault {
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fn default() -> Self {
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Self
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}
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}
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macro_rules! outer {
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($e: expr) => {
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$e
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};
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}
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fn main() {
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let _string: Box<String> = Box::new(Default::default());
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let _byte = Box::new(u8::default());
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let _vec = Box::new(Vec::<u8>::new());
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let _impl = Box::new(ImplementsDefault::default());
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let _impl2 = Box::new(<ImplementsDefault as Default>::default());
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let _impl3: Box<ImplementsDefault> = Box::new(Default::default());
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let _own = Box::new(OwnDefault::default()); // should not lint
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let _in_macro = outer!(Box::new(String::new()));
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let _string_default = outer!(Box::new(String::from("")));
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let _vec2: Box<Vec<ImplementsDefault>> = Box::new(vec![]);
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let _vec3: Box<Vec<bool>> = Box::new(Vec::from([]));
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let _vec4: Box<_> = Box::new(Vec::from([false; 0]));
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let _more = ret_ty_fn();
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call_ty_fn(Box::new(u8::default()));
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issue_10381();
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// `Box::<Option<_>>::default()` would be valid here, but not `Box::default()` or
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// `Box::<Option<[closure@...]>::default()`
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//
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// Would have a suggestion after https://github.com/rust-lang/rust/blob/fdd030127cc68afec44a8d3f6341525dd34e50ae/compiler/rustc_middle/src/ty/diagnostics.rs#L554-L563
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let mut unnameable = Box::new(Option::default());
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let _ = unnameable.insert(|| {});
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}
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fn ret_ty_fn() -> Box<bool> {
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Box::new(bool::default())
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}
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#[allow(clippy::boxed_local)]
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fn call_ty_fn(_b: Box<u8>) {
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issue_9621_dyn_trait();
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}
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use std::io::{Read, Result};
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impl Read for ImplementsDefault {
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fn read(&mut self, _: &mut [u8]) -> Result<usize> {
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Ok(0)
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}
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}
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fn issue_9621_dyn_trait() {
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let _: Box<dyn Read> = Box::new(ImplementsDefault::default());
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issue_10089();
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}
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fn issue_10089() {
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let _closure = || {
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#[derive(Default)]
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struct WeirdPathed;
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let _ = Box::new(WeirdPathed::default());
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};
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}
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fn issue_10381() {
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#[derive(Default)]
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pub struct Foo {}
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pub trait Bar {}
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impl Bar for Foo {}
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fn maybe_get_bar(i: u32) -> Option<Box<dyn Bar>> {
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if i % 2 == 0 {
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Some(Box::new(Foo::default()))
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} else {
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None
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}
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}
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assert!(maybe_get_bar(2).is_some());
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}
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