_cross-scope-placeholders.scss

// Cross-scope compatible placeholder boilerplate.

@mixin my-mixin($extend: true) {
  @if $extend {
    @extend %my-mixin;
  }
  @else {
    // Mixin core
  }
}

%my-mixin {
  @include my-mixin($extend: false);
}

// Example usage.
.my-class {
  @include my-mixin;
}

@media (min-width: 48em) {
  .c {
    @include my-mixin(false);
  }
}