### What it does
Checks for immediate reassignment of fields initialized
with Default::default().

### Why is this bad?
It's more idiomatic to use the [functional update syntax](https://doc.rust-lang.org/reference/expressions/struct-expr.html#functional-update-syntax).

### Known problems
Assignments to patterns that are of tuple type are not linted.

### Example
```
let mut a: A = Default::default();
a.i = 42;
```

Use instead:
```
let a = A {
    i: 42,
    .. Default::default()
};
```