78d6b2ea4e
Removing the semicolon of the last statement of an expressionless block may change the block type even if the statement's type is `()`. If the block type is `!` because of a systematic early return, typing it as `()` may make it incompatible with the expected type for the block (to which `!` is cast).
63 lines
1.2 KiB
Rust
63 lines
1.2 KiB
Rust
//@revisions: edition2021 edition2024
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//@[edition2021] edition:2021
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//@[edition2024] edition:2024
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#![warn(clippy::unnecessary_semicolon)]
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#![feature(postfix_match)]
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#![allow(clippy::single_match)]
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fn no_lint(mut x: u32) -> Option<u32> {
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Some(())?;
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{
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let y = 3;
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dbg!(x + y)
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};
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{
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let (mut a, mut b) = (10, 20);
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(a, b) = (b + 1, a + 1);
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}
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Some(0)
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}
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fn main() {
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let mut a = 3;
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if a == 2 {
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println!("This is weird");
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};
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//~^ ERROR: unnecessary semicolon
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a.match {
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3 => println!("three"),
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_ => println!("not three"),
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};
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//~^ ERROR: unnecessary semicolon
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}
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// This is a problem in edition 2021 and below
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fn borrow_issue() {
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let v = std::cell::RefCell::new(Some(vec![1]));
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match &*v.borrow() {
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Some(v) => {
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dbg!(v);
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},
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None => {},
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};
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}
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fn no_borrow_issue(a: u32, b: u32) {
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match Some(a + b) {
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Some(v) => {
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dbg!(v);
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},
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None => {},
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};
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}
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fn issue14100() -> bool {
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// Removing the `;` would make the block type be `()` instead of `!`, and this could no longer be
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// cast into the `bool` function return type.
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if return true {};
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}
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