once_cell - GitLite

KO | EN

gitlite — search

#hacktoberfest #golang #android #deep-learning #linux #docker #macos #java #windows #awesome #cli #awesome-list #openai #mcp

once_cell

(★ 2,089)

Rust library for single assignment cells and lazy statics without macros

파일 탐색기

최종 버전 다운로드 (.zip)

- - ci.yaml
- icon.png
- logo.png
- bench.rs
- bench_acquire.rs
- lazy_static.rs
- reentrant_init_deadlocks.rs
- regex.rs
- test_synchronization.rs
- imp_cs.rs
- imp_pl.rs
- imp_std.rs
- lib.rs
- race.rs
- - main.rs
  - race.rs
  - race_once_box.rs
  - sync_lazy.rs
  - sync_once_cell.rs
  - unsync_lazy.rs
  - unsync_once_cell.rs
- - main.rs
  - tidy.rs
- Cargo.toml
.gitignore
bors.toml
Cargo.lock.msrv
Cargo.toml
CHANGELOG.md
LICENSE-APACHE
LICENSE-MIT
logo.svg
README.md
rustfmt.toml

# 설치 가이드

1. 코드 내려받기

git clone https://github.com/matklad/once_cell

깃허브에서 프로젝트 코드 전체를 내 컴퓨터로 내려받습니다.

cd once_cell

방금 내려받은 프로젝트 폴더 안으로 이동합니다.

2. Rust

보통 추천

사전 준비물

Git GitHub에서 프로젝트 코드를 내려받으려면 필요합니다.
Rust (rustup) rustup으로 설치하면 cargo도 함께 설치됩니다.

cargo build --release

Rust 프로젝트를 컴파일합니다.

cargo run

빌드 후 바로 실행까지 진행합니다.

✅ cargo build가 에러 없이 끝나면 성공입니다. target/ 폴더에 실행 파일이 생성됩니다.

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

<p align="center"><img src="design/logo.png" alt="once_cell"></p>

[![Build Status](https://github.com/matklad/once_cell/actions/workflows/ci.yaml/badge.svg)](https://github.com/matklad/once_cell/actions)
[![Crates.io](https://img.shields.io/crates/v/once_cell.svg)](https://crates.io/crates/once_cell)
[![API reference](https://docs.rs/once_cell/badge.svg)](https://docs.rs/once_cell/)

# Overview

`once_cell` provides two new cell-like types, `unsync::OnceCell` and `sync::OnceCell`. `OnceCell`
might store arbitrary non-`Copy` types, can be assigned to at most once and provide direct access
to the stored contents. In a nutshell, API looks *roughly* like this:

```rust
impl OnceCell<T> {
    fn new() -> OnceCell<T> { ... }
    fn set(&self, value: T) -> Result<(), T> { ... }
    fn get(&self) -> Option<&T> { ... }
}
```

Note that, like with `RefCell` and `Mutex`, the `set` method requires only a shared reference.
Because of the single assignment restriction `get` can return an `&T` instead of `Ref<T>`
or `MutexGuard<T>`.

`once_cell` also has a `Lazy<T>` type, build on top of `OnceCell` which provides the same API as
the `lazy_static!` macro, but without using any macros:

```rust
use std::{sync::Mutex, collections::HashMap};
use once_cell::sync::Lazy;

static GLOBAL_DATA: Lazy<Mutex<HashMap<i32, String>>> = Lazy::new(|| {
    let mut m = HashMap::new();
    m.insert(13, "Spica".to_string());
    m.insert(74, "Hoyten".to_string());
    Mutex::new(m)
});

fn main() {
    println!("{:?}", GLOBAL_DATA.lock().unwrap());
}
```

More patterns and use-cases are in the [docs](https://docs.rs/once_cell/)!

# Related crates

* [double-checked-cell](https://github.com/niklasf/double-checked-cell)
* [lazy-init](https://crates.io/crates/lazy-init)
* [lazycell](https://crates.io/crates/lazycell)
* [mitochondria](https://crates.io/crates/mitochondria)
* [lazy_static](https://crates.io/crates/lazy_static)
* [async_once_cell](https://crates.io/crates/async_once_cell)
* [generic_once_cell](https://crates.io/crates/generic_once_cell) (bring your own mutex)

Parts of `once_cell` API are included into `std` [as of Rust 1.70.0](https://github.com/rust-lang/rust/pull/105587).