# Bit Roles
[](https://crates.io/crates/bit_roles)
[](https://docs.rs/bit_roles)
This crate enables you to implement granular role and permission management based on bit flags.
<table>
<tr>
<th> Using discrete fields </th>
<th> Using bit roles </th>
</tr>
<tr>
<td>
```rust
#[derive(Debug)]
struct User {
can_send_message: bool,
can_edit_message: bool
}
fn main() {
let user = User {
can_send_message: true,
can_edit_message: false
};
}
```
</td>
<td>
```rust
use bit_roles::BitRole;
#[derive(Debug)]
struct User {
permissions: usize
}
#[derive(Debug, BitRole, Copy, Clone)]
enum Permission {
None = 0,
SendMessage = 1,
EditMessage = 2,
}
fn main() {
let mut permissions = Permission::empty();
permissions.add_one(Permission::SendMessage);
let user = User {
permissions: permissions.get_value()
};
}
```
</td>
</tr>
</table>
## Getting started
Add `bit_roles` to your project:
```shell
cargo add bit_rols
```
## Usage
You can derive the `BitRole` trait for your role enum. It ensures compile-time validation for enum discriminants. Ensure
you specify a discriminant for every enum variant; it must be either zero or a power of two. Also, remember to derive
the `Copy` and `Clone` traits for your enum.
If you need a manager without compile-time checks, it's also exported as `BitRoleUnchecked` trait. This is useful if you
want to use raw integer values for roles or have a complex role enum definition. You will need to implement
the `Into<usize>` trait for your role enum, along with deriving the `Copy` and `Clone` traits for it.