Macro here 

macro_rules! here {
    () => { ... };
    ($msg:literal $(,)?) => { ... };
    ($fmt:expr, $($arg:tt)*) => { ... };
}

Enhanced location macro with support for custom messages

Output format: file_path:line:column[: custom_message]

Features

• No arguments: Returns basic location info (file:line:column)
• Single argument: Location + custom message
• Multiple arguments: Location + formatted message (supports format! syntax)

Return Type

• No arguments: &'static str (compile-time static string)
• With arguments: String (runtime-generated dynamic string)

Examples

Basic usage

println!("Location: {}", here!());
// Example output: src/main.rs:42:10

With static message

println!("Error: {}", here!("Something went wrong"));
// Example output: src/main.rs:42:10: Something went wrong

// Trailing comma supported
println!("Error: {}", here!("Something went wrong",));

Dynamic formatted message

let line_num = 100;
println!("Warning: {}", here!("Check line {}", line_num));
// Example output: src/main.rs:42:10: Check line 100

// Complex formatting
println!("Error: {}", here!("User {} not found, status: {}", "Alice", 404));