A dead-simple, extreme fast permission flag system for Rust with no dependencies.
```rs use fastperm::{add, rm, check};
// Add a flag to a permission digit. asserteq!(add(0, 1), 2); // Remove a flag from a permission digit. asserteq!(rm(2, 1), 0); // Check if a flag is in a permission digit. assert!(check(2, 1)); ```