// This should never be allowed -- since `x` is not `mut`, so `x.0` // cannot be assigned twice. fn var_then_field() { let x: (u32, u32); x = (22, 44); x.0 = 1; //~ ERROR } fn same_field_twice() { let x: (u32, u32); x.0 = 1; //~ ERROR x.0 = 22; x.1 = 44; } fn main() { }