// check-pass #![warn(drop_copy)] use std::mem::drop; use std::vec::Vec; #[derive(Copy, Clone)] struct SomeStruct; struct AnotherStruct { x: u8, y: u8, z: Vec, } impl Clone for AnotherStruct { fn clone(&self) -> AnotherStruct { AnotherStruct { x: self.x, y: self.y, z: self.z.clone(), } } } fn main() { let s1 = SomeStruct {}; let s2 = s1; let s3 = &s1; let mut s4 = s1; let ref s5 = s1; drop(s1); //~ WARN calls to `std::mem::drop` drop(s2); //~ WARN calls to `std::mem::drop` drop(s3); //~ WARN calls to `std::mem::drop` drop(s4); //~ WARN calls to `std::mem::drop` drop(s5); //~ WARN calls to `std::mem::drop` let a1 = AnotherStruct { x: 255, y: 0, z: vec![1, 2, 3], }; let a2 = &a1; let mut a3 = a1.clone(); let ref a4 = a1; let a5 = a1.clone(); drop(a2); //~ WARN calls to `std::mem::drop` drop(a3); drop(a4); //~ WARN calls to `std::mem::drop` drop(a5); } #[allow(unused)] #[allow(clippy::unit_cmp)] fn issue9482(x: u8) { fn println_and(t: T) -> T { println!("foo"); t } match x { // Don't lint (copy type), we only care about side-effects 0 => drop(println_and(12)), // Don't lint (no copy type), we only care about side-effects 1 => drop(println_and(String::new())), 2 => { // Lint, even if we only care about the side-effect, it's already in a block drop(println_and(13)); //~ WARN calls to `std::mem::drop` }, // Lint, idiomatic use is only in body of `Arm` 3 if drop(println_and(14)) == () => (), //~ WARN calls to `std::mem::drop` // Lint, not a fn/method call 4 => drop(2),//~ WARN calls to `std::mem::drop` _ => (), } }