lib.rs:

Rust的字符串重用

示例

use string_intern::{Validator, Symbol};

struct UserIdSymbol;

// This symbol may contain anything
impl Validator for UserIdSymbol {
    // Use an error from standard library to make example shorter
    type Err = ::std::string::ParseError;
    fn validate_symbol(val: &str) -> Result<(), Self::Err> {
        Ok(())
    }
}

/// Actual symbol type you will use in code
type UserId = Symbol<UserIdSymbol>;

// Create from const (panics on invalid input)
let x = UserId::from("user1");
// Create from user input
let y: UserId = format!("user{}", 1).parse().unwrap();
// Both point to the same bytes
assert!(x[..].as_bytes() as *const _ == y[..].as_bytes() as *const _);