@function __add($augend, $addend, $args...) {
  $augend: __parse-float($augend);
  $addend: __parse-float($addend);

  $units: __map($augend $addend, __unit);
  $unit-groups: __map($units, __unit-group);

  $unit-groups-equal: if(
    __every($unit-groups, __is-equal null),
    __is-equal($units...),
    __is-equal($unit-groups...)
  );

  @if ($unit-groups-equal == false and __every($units)) {
    @return calc(#{unquote("#{$augend} + #{$addend}")});
  }

  @return $augend + $addend;
}

///
/// Adds two numbers.
///
/// @access public
/// @group Math
/// @param {number} $augend The first number to add.
/// @param {number} $addend The second number to add.
/// @returns {number} Returns the sum.
/// @example scss
/// $foo: _add(6, 4);
/// // => 10

@function _add($args...) {
  @return call(get-function("__add"), $args...);
}

/// @alias _add

@function \+ ($args...) {
  @return call(get-function("__add"), $args...);
}