Offer Cell

一个 Rust 库，用于定义一种模式，提供对存储数据的引用，并可选地转移该数据的所有权。

使用方法

初始化

// a cell may be created
let cell = OfferCell::new(42);

// or initialzed as empty
let empty = OfferCell::empty();

访问数据

// access the item as a reference
match cell.item() {
    Some(value) = (), // do something with the value
    None => (), // returns none if there is no item
}

// access the item as a mutable reference
match cell.item_mut() {
    Some(value) = (), // do something with the value
    None => (), // returns none if there is no item
}

提供数据

此库的独特之处在于单元内的数据可以被 "提供"

// if the cell contains an item, it can be offered
let offered = cell.offer() {
    Some(offered) => offered,
    None => return,
};

// the offered item implements Deref and DerefMut
assert_eq!(offered.deref(), &42);

// if nothing else is done with the offered item,
// the data will stay in the cell for later

// alternatively the offering can be consumed
// this leaves nothing in the cell, and takes ownership of the data
let data = offered.take();