// mixin for clearfix



        @mixin      clearfix    ()      { &:before,
  &:after {
                content:" ";
    display              : table;  }

  &:after        {clear: both;}
   }.class
{
       padding:10px;@include        clearfix();}
     .base {  color: red;  } // placeholder

%base
{


padding: 12px
}

.foo{ 
@extend      .base;}

.bar     
      {     @extend            %base;

}