rust/tests/ui/lint/drop_copy.rs
2023-05-10 19:36:01 +02:00

80 lines
1.8 KiB
Rust

// 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<u8>,
}
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) -> 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`
_ => (),
}
}