Generate and parse UUIDs.
Provides support for Universally Unique Identifiers (UUIDs). A UUID is a unique 128-bit number, stored as 16 octets. UUIDs are used to assign unique identifiers to entities without requiring a central allocating authority.
They are particularly useful in distributed systems, though they can be used in disparate areas, such as databases and network protocols. Typically a UUID is displayed in a readable string form as a sequence of hexadecimal digits, separated into groups by hyphens.
The uniqueness property is not strictly guaranteed, however for all practical purposes, it can be assumed that an unintentional collision would be extremely unlikely.
To get started with generating random UUIDs, add this to your Cargo.toml:
toml
[dependencies.uuid]
version = "1"
features = ["v4", "fast-rng"]
and then call Uuid::new_v4 in your code:
```rust use uuid::Uuid;
let myuuid = Uuid::newv4(); ```
You can also parse UUIDs without needing any crate features:
```rust use uuid::{Uuid, Version};
let myuuid = Uuid::parsestr("67e55044-10b1-426f-9247-bb680e5fe0c8")?;
asserteq!(Some(Version::Random), myuuid.get_version()); ```
You can parse UUIDs at compile time instead of at runtime.
If you add the macro-diagnostics feature then you can see much better
error messages.
```rust
extern crate uuid;
let my_uuid = uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8")?;
asserteq!(Some(Version::Random), myuuid.get_version()); ```
By default, this crate depends on nothing but std and cannot generate
[Uuid]s. You need to enable the following Cargo features to enable
various pieces of functionality:
v1 - adds the Uuid::new_v1 function and the ability to create a V1
using an implementation of uuid::v1::ClockSequence (usually
uuid::v1::Context) and a timestamp from time::timespec.v3 - adds the Uuid::new_v3 function and the ability to create a V3
UUID based on the MD5 hash of some data.v4 - adds the Uuid::new_v4 function and the ability to randomly
generate a Uuid.v5 - adds the Uuid::new_v5 function and the ability to create a V5
UUID based on the SHA1 hash of some data.macro-diagnostics - enhances the diagnostics of uuid! macro.serde - adds the ability to serialize and deserialize a Uuid using the
serde crate.arbitrary - adds an Arbitrary trait implementation to Uuid.fast-rng - when combined with v4 uses a faster algorithm for generating
random UUIDs. This feature requires more dependencies to compile, but is just
as suitable for UUIDs as the default algorithm.You need to enable one of the following Cargo features together with the
v4 feature if you're targeting wasm32-unknown-unknown target:
js - enables support for randomness on
wasm32-unknown-unknown via [getrandom]Alternatively, you can provide a custom getrandom implementation yourself
via getrandom::register_custom_getrandom.
Some features are unstable. They may be incomplete or depend on other unstable libraries. These include:
zerocopy-unstable - adds support for zero-copy deserialization using the zerocopy library.Unstable features may break between minor releases.
To allow unstable features, you'll need to enable the Cargo feature as normal, but also pass an additional
flag through your environment to opt-in to unstable uuid features:
RUSTFLAGS="--cfg uuid_unstable"
The minimum supported Rust version for uuid is documented in
CI. It may be bumped in minor releases as necessary.
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.