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