Choosing use vendor prefix or not by like hash for Sass

gistfile1.scss

$use:
  -webkit-, true,
  -moz-,    true,
  -o-,      true,
  -ms-,     false;

@mixin addPrefix($property, $value, $def: false) {
  $property: unquote($property);
  $value: unquote($value);
  @for $i from 1 through length($use)/2 {
    $n: $i * 2;
    $flg: nth($use, $n);
    $prfx: nth($use, $n - 1);
    @if $def {
      $_index: index($def, $prfx);
      @if $_index {
        $flg: nth($def, $_index + 1);
      }
    }
    @if $flg {
      #{$prfx + $property}: $value;
    }
  }
  #{$property}: $value;
}

// Usage
// default
@mixin background-size($value) {
@include addPrefix('background-size', $value);
}

// using with default using or not
@mixin box-shadow($value) {
$def:
-webkit-, false,
-ms-, true;
@include addPrefix('box-shadow', $value, $def);
}