rust/tests/ui/half-open-range-patterns/half-open-range-pats-inclusive-dotdotdot-bad-syntax.rs
2023-01-11 09:32:08 +00:00

31 lines
1.1 KiB
Rust

// Test that `...X` range-to patterns are syntactically invalid.
//
// See https://github.com/rust-lang/rust/pull/67258#issuecomment-565656155
// for the reason why. To summarize, we might want to introduce `...expr` as
// an expression form for splatting (or "untupling") in an expression context.
// While there is no syntactic ambiguity with `...X` in a pattern context,
// there's a potential confusion factor here, and we would prefer to keep patterns
// and expressions in-sync. As such, we do not allow `...X` in patterns either.
fn main() {}
#[cfg(FALSE)]
fn syntax() {
match scrutinee {
...X => {} //~ ERROR range-to patterns with `...` are not allowed
...0 => {} //~ ERROR range-to patterns with `...` are not allowed
...'a' => {} //~ ERROR range-to patterns with `...` are not allowed
...0.0f32 => {} //~ ERROR range-to patterns with `...` are not allowed
}
}
fn syntax2() {
macro_rules! mac {
($e:expr) => {
let ...$e; //~ ERROR range-to patterns with `...` are not allowed
}
}
mac!(0);
}