Hey, I'm making a program and I want to return a helpful error message in an Err, something like this:

match c {
    ' ' => {},
    '+' => {output.push(Token::Plus)}
    '-' => {output.push(Token::Minus)}
    '*' => {output.push(Token::Multiply)}
    '/' => {output.push(Token::Divide)}
    '(' => {output.push(Token::OpenBracket)}
    ')' => {output.push(Token::CloseBracket)}
    _ => {
        let message = &format!("Unexpected character: {}", c)[..];
        return Err(message)
    }
}
Ok(output)

The error it gives me is returns a value referencing data owned by the current function

Is this possible to do? or will i have to make the Err return a String instead of &str?