Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.12)
// Compass (v1.0.3)
// ----

//SCSS
@mixin blockOrHidden($boolean:true) {
  @if $boolean {
    @debug "$boolean is #{$boolean}";
      display: block;
    }
    @else {
      @debug "$boolean is #{$boolean}";
      display: none;
    }
}

.block {
  @include blockOrHidden;
}

.hidden{
  @include blockOrHidden(false);
}

SassMeister-output.css

.block {
  display: block;
}

.hidden {
  display: none;
}