rust/tests/ui/or-patterns/nested-undelimited-preceden...

45 lines
1.3 KiB
Rust

// This test tests the precedence of `|` (or-patterns) undelimited nested patterns. In particular,
// we want to reserve the syntactic space of a pattern followed by a type annotation for possible
// future type ascription, so we need to make sure that any time a pattern is followed by type
// annotation (for now), the pattern is not a top-level or-pattern. However, there are also a few
// types of patterns that allow undelimited subpatterns that could cause the same ambiguity.
// Currently, those should be impossible due to precedence rule. This test enforces that.
enum E {
A,
B,
}
fn foo() {
use E::*;
// ok
let b @ (A | B): E = A;
let b @ A | B: E = A; //~ERROR `b` is not bound in all patterns
//~^ ERROR top-level or-patterns are not allowed
}
enum F {
A(usize),
B(usize),
}
fn bar() {
use F::*;
// ok
let (A(x) | B(x)): F = A(3);
let &A(_) | B(_): F = A(3); //~ERROR mismatched types
//~^ ERROR top-level or-patterns are not allowed
let &&A(_) | B(_): F = A(3); //~ERROR mismatched types
//~^ ERROR top-level or-patterns are not allowed
let &mut A(_) | B(_): F = A(3); //~ERROR mismatched types
//~^ ERROR top-level or-patterns are not allowed
let &&mut A(_) | B(_): F = A(3); //~ERROR mismatched types
//~^ ERROR top-level or-patterns are not allowed
}
fn main() {}