rust/tests/ui/drop/lint-tail-expr-drop-order.rs
2024-08-21 01:05:21 +08:00

72 lines
2.2 KiB
Rust

//@ compile-flags: -Z unstable-options
//@ edition: 2024
// Edition 2024 lint for change in drop order at tail expression
// This lint is to capture potential change in program semantics
// due to implementation of RFC 3606 <https://github.com/rust-lang/rfcs/pull/3606>
#![deny(tail_expr_drop_order)]
#![feature(shorter_tail_lifetimes)]
struct LoudDropper;
impl Drop for LoudDropper {
fn drop(&mut self) {
// This destructor should be considered significant because it is a custom destructor
// and we will assume that the destructor can generate side effects arbitrarily so that
// a change in drop order is visible.
println!("loud drop");
}
}
impl LoudDropper {
fn get(&self) -> i32 {
0
}
}
fn should_lint() -> i32 {
let x = LoudDropper;
// Should lint
x.get() + LoudDropper.get()
//~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
//~| WARN: this changes meaning in Rust 2024
}
fn should_lint_closure() -> impl FnOnce() -> i32 {
let x = LoudDropper;
move || x.get() + LoudDropper.get()
//~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
//~| WARN: this changes meaning in Rust 2024
}
fn should_not_lint() -> i32 {
let x = LoudDropper;
// Should not lint
x.get()
}
fn should_not_lint_in_nested_block() -> i32 {
let x = LoudDropper;
// Should not lint because Edition 2021 drops temporaries in blocks earlier already
{ LoudDropper.get() }
}
fn should_not_lint_in_match_arm() -> i32 {
let x = LoudDropper;
// Should not lint because Edition 2021 drops temporaries in blocks earlier already
match &x {
_ => LoudDropper.get(),
}
}
fn should_lint_in_nested_items() {
fn should_lint_me() -> i32 {
let x = LoudDropper;
// Should lint
x.get() + LoudDropper.get()
//~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
//~| WARN: this changes meaning in Rust 2024
}
}
fn main() {}