<===> input.scss
$character-code: f102;

test {

  /* Expected: "\f102" */

  /* Sass 3.4 */
  content: unquote("\"\\#{$character-code}\"");

  /* Sass 3.3 */
  content: str-slice("\x", 1, 1) + $character-code;

}
<===> output.css
test {
  /* Expected: "\f102" */
  /* Sass 3.4 */
  content: "\f102";
  /* Sass 3.3 */
  content: "xf102";
}