### What it does
Checks for types used in structs, parameters and `let`
declarations above a certain complexity threshold.

### Why is this bad?
Too complex types make the code less readable. Consider
using a `type` definition to simplify them.

### Example
```
struct Foo {
    inner: Rc<Vec<Vec<Box<(u32, u32, u32, u32)>>>>,
}
```