django-compass-mixins/compass_mixins/static/breakpoint/parsers/double/_default.scss

@function breakpoint-parse-double-default($first, $second) {
  $feature: '';
  $value: '';

  @if type-of($first) == 'string' {
    $feature: $first;
    $value: $second;
  }
  @else {
    $feature: $second;
    $value: $first;
  }

  // Set Context
  $context-setter: private-breakpoint-set-context($feature, $value);

  @if (breakpoint-get('to ems') == true) {
    $value: breakpoint-to-base-em($value);
  }

  @return '(#{$feature}: #{$value})'
}