non_empty_string/
macros.rs

1#[macro_export]
2/// Creates a `NonEmptyString` from a string literal at compile time.
3///
4/// This macro ensures that the provided string is **not empty** at compile time,
5/// preventing runtime errors due to empty strings.
6///
7/// # Examples
8///
9/// ```
10/// use non_empty_string::{non_empty, NonEmptyString};
11///
12/// let s: NonEmptyString = non_empty!("Hello, Rust!");
13/// assert_eq!(s, NonEmptyString::new("Hello, Rust!".to_string()).unwrap());
14/// ```
15///
16/// # Compile-time Failure
17///
18/// If an empty string is provided, this macro will cause a **compile-time error**.
19///
20/// ```compile_fail
21/// use non_empty_string::non_empty;
22///
23/// let s = non_empty!("");
24/// ```
25macro_rules! non_empty {
26    ($s:expr) => {{
27        // Compile-time assertion to ensure the string is non-empty
28        const _: () = assert!(!$s.is_empty(), "String cannot be empty");
29
30        // Create a NonEmptyString, unsafely wrapping since we've checked it's valid
31        unsafe { NonEmptyString::new_unchecked($s.to_string()) }
32    }};
33}
34
35#[cfg(test)]
36mod tests {
37    use crate::NonEmptyString;
38
39    #[test]
40    fn test_non_empty_string_macro_valid() {
41        let s = non_empty!("Test String");
42        assert_eq!(s, NonEmptyString::try_from("Test String").unwrap());
43    }
44}
non_empty_string/macros.rs

non_empty_string/
macros.rs
