const x = 0; // errors: const cannot be reassigned x++; x--; x += 0; x -= 0; x /= 0; x %= 0; x <<= 0 x >>= 0; x >>>= 0; x |= 0; x ^= 0; x &= 0; // regression tests -- OK to assign consts like this: const { foo } = { foo: "foo" } const [ bar ] = ["bar"]; (foo: number); // error: string ~> number (bar: number); // error: string ~> number declare var bazzes: { baz: string }[]; for (const { baz } of bazzes) { (baz: number); // error: string ~> number }