Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="container">
     <div class="test">hello</div>
     <div class="test2">hello</div>
     <div class="test">hello</div>
</div>

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

@import 'susy';

.some-selector {

   @include span(5);

   [dir='rtl'] & {
      @include with-layout(rtl) {
         @include span(5);
      }
   }

}

SassMeister-output.css

.some-selector {
  width: 126.31579%;
  float: left;
  margin-right: 5.26316%;
}

[dir='rtl'] .some-selector {
  width: 126.31579%;
  float: right;
  margin-left: 5.26316%;
}

SassMeister-rendered.html

<div class="container">
     <div class="test">hello</div>
     <div class="test2">hello</div>
     <div class="test">hello</div>
</div>