1 // Test that `...X` range-to patterns are syntactically invalid.
2 //
3 // See https://github.com/rust-lang/rust/pull/67258#issuecomment-565656155
4 // for the reason why. To summarize, we might want to introduce `...expr` as
5 // an expression form for splatting (or "untupling") in an expression context.
6 // While there is no syntactic ambiguity with `...X` in a pattern context,
7 // there's a potential confusion factor here, and we would prefer to keep patterns
8 // and expressions in-sync. As such, we do not allow `...X` in patterns either.
9
10 #![feature(half_open_range_patterns)]
11
main()12 fn main() {}
13
14 #[cfg(FALSE)]
syntax()15 fn syntax() {
16 match scrutinee {
17 ...X => {} //~ ERROR range-to patterns with `...` are not allowed
18 ...0 => {} //~ ERROR range-to patterns with `...` are not allowed
19 ...'a' => {} //~ ERROR range-to patterns with `...` are not allowed
20 ...0.0f32 => {} //~ ERROR range-to patterns with `...` are not allowed
21 }
22 }
23
syntax2()24 fn syntax2() {
25 macro_rules! mac {
26 ($e:expr) => {
27 let ...$e; //~ ERROR range-to patterns with `...` are not allowed
28 }
29 }
30
31 mac!(0);
32 }
33