// run-rustfix #![allow( unused, clippy::no_effect, clippy::redundant_closure_call, clippy::many_single_char_names, clippy::needless_pass_by_value, clippy::option_map_unit_fn )] #![warn( clippy::redundant_closure, clippy::redundant_closure_for_method_calls, clippy::needless_borrow )] use std::path::PathBuf; fn main() { let a = Some(1u8).map(foo); meta(foo); let c = Some(1u8).map(|a| {1+2; foo}(a)); let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted? all(&[1, 2, 3], &2, |x, y| below(x, y)); //is adjusted unsafe { Some(1u8).map(|a| unsafe_fn(a)); // unsafe fn } // See #815 let e = Some(1u8).map(|a| divergent(a)); let e = Some(1u8).map(generic); let e = Some(1u8).map(generic); // See #515 let a: Option<Box<dyn (::std::ops::Deref<Target = [i32]>)>> = Some(vec![1i32, 2]).map(|v| -> Box<dyn (::std::ops::Deref<Target = [i32]>)> { Box::new(v) }); } trait TestTrait { fn trait_foo(self) -> bool; fn trait_foo_ref(&self) -> bool; } struct TestStruct<'a> { some_ref: &'a i32, } impl<'a> TestStruct<'a> { fn foo(self) -> bool { false } unsafe fn foo_unsafe(self) -> bool { true } } impl<'a> TestTrait for TestStruct<'a> { fn trait_foo(self) -> bool { false } fn trait_foo_ref(&self) -> bool { false } } impl<'a> std::ops::Deref for TestStruct<'a> { type Target = char; fn deref(&self) -> &char { &'a' } } fn test_redundant_closures_containing_method_calls() { let i = 10; let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo); let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo); let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo); let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref()); let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo); let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear); let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear); unsafe { let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe()); } let e = Some("str").map(std::string::ToString::to_string); let e = Some("str").map(str::to_string); let e = Some('a').map(char::to_uppercase); let e = Some('a').map(char::to_uppercase); let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect(); let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect(); let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect(); let p = Some(PathBuf::new()); let e = p.as_ref().and_then(|s| s.to_str()); let c = Some(TestStruct { some_ref: &i }) .as_ref() .map(|c| c.to_ascii_uppercase()); fn test_different_borrow_levels<T>(t: &[&T]) where T: TestTrait, { t.iter().filter(|x| x.trait_foo_ref()); t.iter().map(|x| x.trait_foo_ref()); } let mut some = Some(|x| x * x); let arr = [Ok(1), Err(2)]; let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect(); } struct Thunk<T>(Box<dyn FnMut() -> T>); impl<T> Thunk<T> { fn new<F: 'static + FnOnce() -> T>(f: F) -> Thunk<T> { let mut option = Some(f); // This should not trigger redundant_closure (#1439) Thunk(Box::new(move || option.take().unwrap()())) } fn unwrap(self) -> T { let Thunk(mut f) = self; f() } } fn foobar() { let thunk = Thunk::new(|| println!("Hello, world!")); thunk.unwrap() } fn meta<F>(f: F) where F: Fn(u8), { f(1u8) } fn foo(_: u8) {} fn foo2(_: u8) -> u8 { 1u8 } fn all<X, F>(x: &[X], y: &X, f: F) -> bool where F: Fn(&X, &X) -> bool, { x.iter().all(|e| f(e, y)) } fn below(x: &u8, y: &u8) -> bool { x < y } unsafe fn unsafe_fn(_: u8) {} fn divergent(_: u8) -> ! { unimplemented!() } fn generic<T>(_: T) -> u8 { 0 } fn passes_fn_mut(mut x: Box<dyn FnMut()>) { requires_fn_once(|| x()); } fn requires_fn_once<T: FnOnce()>(_: T) {} fn test_redundant_closure_with_function_pointer() { type FnPtrType = fn(u8); let foo_ptr: FnPtrType = foo; let a = Some(1u8).map(foo_ptr); } fn test_redundant_closure_with_another_closure() { let closure = |a| println!("{}", a); let a = Some(1u8).map(closure); } fn make_lazy(f: impl Fn() -> fn(u8) -> u8) -> impl Fn(u8) -> u8 { // Currently f is called when result of make_lazy is called. // If the closure is removed, f will be called when make_lazy itself is // called. This changes semantics, so the closure must stay. Box::new(move |x| f()(x)) } fn call<F: FnOnce(&mut String) -> String>(f: F) -> String { f(&mut "Hello".to_owned()) } fn test_difference_in_mutability() { call(|s| s.clone()); } struct Bar; impl std::ops::Deref for Bar { type Target = str; fn deref(&self) -> &str { "hi" } } fn test_deref_with_trait_method() { let _ = [Bar].iter().map(|s| s.to_string()).collect::<Vec<_>>(); }