This are Custom Enums
for memorable and uniform response codes.
Enums are cheaper to compare and harder to get wrong than strings thereby guaranteeing efficiency.
```rust use custom_codes::FileOps;
fn createfile(filename: &str) -> FileOps { match std::fs::File::create(filename) { Ok() => FileOps::CreateTrue, Err(_) => FileOps::CreateFalse, } }
fn main() { open("foo.txt"); } ```