rust/src/test/compile-fail/mut-cant-alias.rs
Kiet Tran b3290d322e Make some borrow checker errors more user friendly
A mutable and immutable borrow place some restrictions on what you can
with the variable until the borrow ends. This commit attempts to convey
to the user what those restrictions are. Also, if the original borrow is
a mutable borrow, the error message has been changed (more specifically,
i. "cannot borrow `x` as immutable because it is also borrowed as
mutable" and ii. "cannot borrow `x` as mutable more than once" have
been changed to "cannot borrow `x` because it is already borrowed as
mutable").

In addition, this adds a (custom) span note to communicate where the
original borrow ends.
2014-01-23 14:44:28 -05:00

19 lines
681 B
Rust

// Copyright 2013 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.
use std::cell::RefCell;
fn main() {
let m = RefCell::new(0);
let mut b = m.borrow_mut();
let b1 = b.get();
let b2 = b.get(); //~ ERROR cannot borrow `b` because it is already borrowed as mutable
}