# Later Operator
[](https://docs.rs/later_operator/)
[](https://github.com/Blobfolio/later_operator/blob/master/CHANGELOG.md)
[](https://crates.io/crates/later_operator)
[](https://github.com/Blobfolio/later_operator/actions)
[](https://deps.rs/repo/github/blobfolio/later_operator)
[](https://en.wikipedia.org/wiki/WTFPL)
[](https://github.com/Blobfolio/later_operator/issues)
This library provides a `ComparisonOperator` enum that can be used to parse, store, evaluate, and/or print Rust's relational operators: `!=`, `<`, `<=`, `==`, `>=`, `>`.
## Examples
```rust
use later_operator::ComparisonOperator;
// Parse from a string, then compare two arbitrary values.
let op = ComparisonOperator::try_from("<=").unwrap();
assert!(op.compare(&3_u8, &u8::MAX)); // 3 <= 255
// Re-stringify the operator for printing or whatever.
assert_eq!(
format!("3 {op} 255"),
"3 <= 255",
);
// Leading/trailing whitespace is ignored when parsing.
assert_eq!(
ComparisonOperator::try_from("==").unwrap(),
ComparisonOperator::try_from(" ==\n").unwrap(),
);
// But the value has to make sense or it will fail.
assert!(ComparisonOperator::try_from("~").is_err());
```
When the optional `serde` crate feature is enabled, `ComparisonOperator` can be de/serialized as a string too:
```rust
use later_operator::ComparisonOperator;
use serde::{Deserialize, Serialize};
#[derive(Debug, Clone, Deserialize, Serialize)]
struct AffectedVersion {
operator: ComparisonOperator,
version: String,
}
```
## Installation
Add `later_operator` to your `dependencies` in `Cargo.toml`, like:
```toml
[dependencies]
later_operator = "0.4.*"
```