| //! Check that braces has the expected precedence in relation to index op and some arithmetic |
| //! bin-ops involving nested braces. |
| //! |
| //! This is a regression test for [Wrapping expr in curly braces changes the operator precedence |
| //! #28777](https://github.com/rust-lang/rust/issues/28777), which was fixed by |
| //! <https://github.com/rust-lang/rust/pull/30375>. |
| |
| //@ run-pass |
| |
| fn that_odd_parse(c: bool, n: usize) -> u32 { |
| let x = 2; |
| let a = [1, 2, 3, 4]; |
| let b = [5, 6, 7, 7]; |
| x + if c { a } else { b }[n] |
| } |
| |
| /// See [Wrapping expr in curly braces changes the operator precedence |
| /// #28777](https://github.com/rust-lang/rust/issues/28777). This was fixed by |
| /// <https://github.com/rust-lang/rust/pull/30375>. #30375 added the `that_odd_parse` example above, |
| /// but that is not *quite* the same original example as reported in #28777, so we also include the |
| /// original example here. |
| fn check_issue_28777() { |
| // Before #30375 fixed the precedence... |
| |
| // ... `v1` evaluated to 9, indicating a parse of `(1 + 2) * 3`, while |
| let v1 = { 1 + { 2 } * { 3 } }; |
| |
| // `v2` evaluated to 7, indicating a parse of `1 + (2 * 3)`. |
| let v2 = 1 + { 2 } * { 3 }; |
| |
| // Check that both now evaluate to 7, as was fixed by #30375. |
| assert_eq!(v1, 7); |
| assert_eq!(v2, 7); |
| } |
| |
| fn main() { |
| assert_eq!(4, that_odd_parse(true, 1)); |
| assert_eq!(8, that_odd_parse(false, 1)); |
| |
| check_issue_28777(); |
| } |
