error borrow-conflict

What it means#

While an exclusive borrow &var x exists there can be no other borrow and no access to x; while shared borrows &x exist, x cannot be modified (§7.2).

Example#

fn main() {
  var xs = [1, 2, 3]
  let first = &xs
  xs.push(4)      // <- borrow-conflict
  print(first.len())
}

borrow-conflict

How to fix#

fn main() {
  var xs = [1, 2, 3]
  let first = &xs
  print(first.len())
  xs.push(4)
}

End the shared borrow (stop using it) before mutating, or restructure so that the two accesses do not overlap.

See also#

• use-after-move
• borrow-escape
• mutate-immutable