C ++: insert negative character value in string literal?

I have a text renderer that uses negative char values ​​from strings to render native characters in a font that I made instead of plain ascii text.

text.write("Hello! _"); // insert a heart at the underscore somehow...
                        // the heart value is char -10

      

        
        
        
      

    

Is it possible to get a negative char value written statically inside double quotes? Or is there a way to do this outside of the quotes, but still as a string literal?

Edit:

To clarify a bit, I have to use an array char

in this particular case, unfortunately. The code inside uses std::string

, and all positive values ​​are taken over the standard ascii clays. My goal is to be able to enter a negative number to represent additional characters in a string literal. Thus, the following would be true:

const char * literal = "a literal w/ a negative char value as the 10th element"
literal[9] == -10; // would be true