unused_parens_json_suggestion.rs

// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// compile-flags: --error-format pretty-json -Zunstable-options
// compile-pass

// The output for humans should just highlight the whole span without showing
// the suggested replacement, but we also want to test that suggested
// replacement only removes one set of parentheses, rather than naïvely
// stripping away any starting or ending parenthesis characters—hence this
// test of the JSON error format.

#![warn(unused_parens)]

fn main() {
    // We want to suggest the properly-balanced expression `1 / (2 + 3)`, not
    // the malformed `1 / (2 + 3`
    let _a = (1 / (2 + 3));
    f();
}

fn f() -> bool {
    loop {
        if (break { return true }) {
        }
    }
    false
}