Clusterfuck rem mixin

gistfile1.sass

/ Fluid Squares
// -------------------------------------------------------
@mixin box($box-size: 4rem, $fluid: false) {
  display: inline-block;
  position: relative;
  width: $box-size;
  text-align: center;
  @if($fluid) {
    height: 0;
    padding-bottom: $box-size;
  }
  @else {
    height: $box-size;
  }

  .box--diamond__content {
    width: $box-size;
    height: $box-size;
  }
}

// Diamonds
// -------------------------------------------------------
@mixin diamond($degrees: 45deg) {
  display: inline-block;
  position: relative;
  text-decoration: none;
  overflow: hidden;
  @include rotate($degrees);
  
  .box--diamond__content {
    display: table-cell;
    vertical-align: middle;
    padding: 1rem;
    @include rotate(-$degrees);
  }
}

// Rem - Px fallback
// -------------------------------------------------------
@function parseInt($n) { /* [2] */
  @return $n / ($n * 0 + 1);
}

@mixin rem($property, $values) {
  $px : (); /* [3] */
  $rem: (); /* [3] */
  
  @each $value in $values { /* [4] */
   
    @if $value == 0 or $value == auto { /* [5] */
      $px : append($px , $value);
      $rem: append($rem, $value);
    }
    
    @else { 
      $unit: unit($value); /* [6] */
      $val: parseInt($value); /* [6] */
      
      @if $unit == "px" { /* [7] */
        $px : append($px,  $value);
        $rem: append($rem, ($val / 10 * 1rem));
      }
      
      @if $unit == "rem" { /* [7] */
        $px : append($px,  ($val * 10 * 1px));
        $rem: append($rem, $value);
      }
    }
  }
  
  #{$property}: $px;  /* [8] */
  #{$property}: $rem; /* [8] */
}