Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.2.17)
// Compass (v0.12.4)
// ----

@mixin extend($class: foo, $extend: true) {
  @if $extend {
    @extend %#{$class};
  }
  @else {
    @if ($class == clear) {
      clear: both;
    }
    @else if ($class == border-box) {
      box-sizing: border-box;
    }
  }
}

%clear {
  @include extend(clear, false);
}

%border-box {
  @include extend(border-box, false);
}

.clear {
  @include extend(clear);
}

@media (min-width: 100px) {
  .clear-in-mq {
    @include extend(clear, false);
  }
}

.border-box {
  @include extend(border-box);
}

.another-border-box {
  @include extend(border-box);
}

@media (min-width: 100px) {
  .border-box-in-mq {
    @include extend(border-box, false);
  }
}

SassMeister-output.css

.clear {
  clear: both;
}

.border-box, .another-border-box {
  box-sizing: border-box;
}

@media (min-width: 100px) {
  .clear-in-mq {
    clear: both;
  }
}
@media (min-width: 100px) {
  .border-box-in-mq {
    box-sizing: border-box;
  }
}