Generated by SassMeister.com.

SassMeister-input.scss

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

%colors {
  &.error {
    color: red;
  }
  
  &.success {
    color: green;
  }
}

.button {
  border-radius: .25em;
  @extend %colors;
}

.foo {
  @extend %colors.error;
}

SassMeister-output.css

.error.button, .foo {
  color: red;
}
.success.button {
  color: green;
}

.button {
  border-radius: .25em;
}