A Rust macro for defining integer-backed opaque types safely.

Originally inspired by code from Redox OS, this crate provides a convenient way to create new types that are backed by primitive integers (typically usize), providing type safety without compromising performance.

• Create simple opaque types backed by any integer type
• Generate corresponding atomic types with thread-safe operations
• Zero-cost abstraction - the new types have the same size as their backing types
• Full support for common derives (Debug, Clone, Copy, Hash, Eq, PartialEq, Ord, PartialOrd)

Add this to your Cargo.toml:

[dependencies]
int_like = "0.1.0"

Define a simple type backed by usize:

use int_like::int_like;

/// Define an opaque type `Pid` backed by a `usize`.
int_like!(Pid, usize);

const ZERO: Pid = Pid::from(0);
let pid = Pid::from(42);
assert_eq!(pid.into(), 42);

Define both a regular type and its atomic counterpart:

use int_like::int_like;
use std::sync::atomic::Ordering;

/// Define opaque types `Pid` and `AtomicPid`, backed respectively by a `usize`
/// and an `AtomicUsize`.
int_like!(Pid, AtomicPid, usize, AtomicUsize);

const ZERO: Pid = Pid::from(0);
let ATOMIC_PID: AtomicPid = AtomicPid::default();

// Atomic operations
ATOMIC_PID.store(Pid::from(100), Ordering::SeqCst);
let value = ATOMIC_PID.load(Ordering::SeqCst);
assert_eq!(value, Pid::from(100));

For simple types:

• from(x: T) -> Self - Create from the backing type
• new(x: T) -> Self - Alternative constructor
• into() -> T - Convert back to the backing type
• data() -> T - Get the backing value

For atomic types:

• new(x: T) -> Self - Create from the non-atomic type
• default() -> Self - Create with zero value
• load(ordering) -> T - Atomic load
• store(val, ordering) - Atomic store
• swap(val, ordering) -> T - Atomic swap
• compare_exchange(current, new, success, failure) -> Result<T, T> - CAS operation
• compare_exchange_weak(current, new, success, failure) -> Result<T, T> - Weak CAS
• fetch_add(val, ordering) -> T - Atomic add

This project is licensed under the MIT License - see the LICENSE file for details.