rust/tests/ui/try-trait/try-operator-expansion-hygiene.rs
2025-07-10 18:47:20 +05:00

25 lines
650 B
Rust

//! This test verifies that the `?` operator expansion is hygienic,
//! i.e., it's not affected by other `val` and `err` bindings that may be in scope.
//!
//! Note: Prior to the Try trait stabilization, `expr?` expanded to a match
//! with `val` and `err` bindings. The current implementation uses Try::branch()
//! but this test remains relevant for hygiene verification.
//@ run-pass
#![allow(non_upper_case_globals)]
#![allow(dead_code)]
use std::num::ParseIntError;
fn main() {
assert_eq!(parse(), Ok(1));
}
fn parse() -> Result<i32, ParseIntError> {
const val: char = 'a';
const err: char = 'b';
Ok("1".parse::<i32>()?)
}