error not-assignable

What it means#

The left side of = or a compound assignment MUST be a mutable place: a var variable, a field of one, or an element accessed through &var (§5.1). A call result, a literal or an arithmetic expression is not a place. (Assignment to an existing immutable let binding is mutate-immutable.)

Example#

fn total() -> i32 => 10

fn main() {
  total() = 5      // <- not-assignable
}

not-assignable

How to fix#

fn main() {
  var total = 10
  total = 5
}

Assign to a variable, field or element instead of an expression value.

See also#

• mutate-immutable
• borrow-conflict