Shorthand Sass Extend

extend-shorthand.css

.foo, .bar {
  background: red;
}

extend-shorthand.sass

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

// add this mixin to your Sass file:
@mixin ext($name, $silent: false)
  @if $silent == true
    @extend %#{$name} !optional
  @else
    @extend .#{$name} !optional
 
// then you may extend other classes in a shorter format:
 
%foo
  background: red
 
.bar
  +ext(foo, true)
  //instead of:
  //@extend .foo !optional
 

SassMeister-output.css

.bar {
  background: red;
}