Implemented macro for compile time non empty string creation

This is more convenient for constant strings in the codebase that are
known to be non empty.

Author: patskovn

Cargo.toml

@@ -25,6 +25,7 @@ serde = { version = "1", features = ["derive"] }
 
 [features]
 default = []
+macro = []
 serde = ["dep:serde"]
 
 

src/lib.rs

@@ -17,6 +17,9 @@ use delegate::delegate;
 #[cfg(feature = "serde")]
 mod serde_support;
 
+#[cfg(feature = "macro")]
+mod macros;
+
 mod trait_impls;
 
 /// A simple String wrapper type, similar to NonZeroUsize and friends.

src/macros.rs

@@ -0,0 +1,44 @@
+#[macro_export]
+/// Creates a `NonEmptyString` from a string literal at compile time.
+///
+/// This macro ensures that the provided string is **not empty** at compile time,
+/// preventing runtime errors due to empty strings.
+///
+/// # Examples
+///
+/// ```
+/// use non_empty_string::{non_empty, NonEmptyString};
+///
+/// let s: NonEmptyString = non_empty!("Hello, Rust!");
+/// assert_eq!(s, NonEmptyString::new("Hello, Rust!".to_string()).unwrap());
+/// ```
+///
+/// # Compile-time Failure
+///
+/// If an empty string is provided, this macro will cause a **compile-time error**.
+///
+/// ```compile_fail
+/// use non_empty_string::non_empty;
+///
+/// let s = non_empty!("");
+/// ```
+macro_rules! non_empty {
+    ($s:expr) => {{
+        // Compile-time assertion to ensure the string is non-empty
+        const _: () = assert!(!$s.is_empty(), "String cannot be empty");
+
+        // Create a NonEmptyString, unsafely wrapping since we've checked it's valid
+        unsafe { NonEmptyString::new_unchecked($s.to_string()) }
+    }};
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::NonEmptyString;
+
+    #[test]
+    fn test_non_empty_string_macro_valid() {
+        let s = non_empty!("Test String");
+        assert_eq!(s, NonEmptyString::try_from("Test String").unwrap());
+    }
+}