ref_wrapper 0.3.0

ref_wrapper
===

Wrapper of dynamically borrowed data.

*The author of this crate is not good at English.*  
*Forgive me if the document is hard to read.*

## ⚠ Warning!!!


This crate is not recommended.

Because we found `unsafe` misuse in this crate. Specifically,
references obtained though `RefWrap` become dangling references
after the `RefWrap` destroyed. 

Instead, we create [`ref_iter`] Crate.  
However, this one targets only iterators.

[`ref_iter`]:https://crates.io/crates/ref_iter

## What is this?


This crate provide wrappers for value generated from dynamic borrowing types.

| Wrapper      | Target   |
|--------------|----------|
| `RefWrap`    | `Ref`    |
| `RefWrapMut` | `RefMut` |

## Examples


Normal use case.

```rust
let src = RefCell::new(vec![1, 2, 3]);
let target = RefWrap::new(src.borrow(), |x| VecStat(x));
assert_eq!(target.summary(), 6);

pub struct VecStat<'a>(&'a Vec<i32>);
impl<'a> VecStat<'a> {
    pub fn summary(&self) -> i32 {
        self.0.iter().sum::<i32>()
    }
}
```

Iterator use case.

```rust
let src = RefCell::new(vec![1, 2, 3]);
let iter = RefWrap::new(src.borrow(), |x| x.iter());
assert_eq!(iter.sum::<i32>(), 6);
```

## What's new.


v0.3.0

* Notice of non-recommendation.

v0.2.2

* Remove unused lifetime constraint of `RefIter::new` and `RefIterMut::new`.
* Minor refactoring.

v0.2.1

* Minor refactoring.

v0.2.0

* Crate is now `no_std`.
* `new` method callback argument returns no longer need to wrapped in `Box`.
* `RefWrap` and `RefWrapMut` implement `Iterator` in certain cases.
* Instead of the above, `RefIter` and `RefIterMut` have been removed.

v0.1.3-0.1.5

* Minor refactoring.

v0.1.2

* Some internal function is inlined.