Porting Bootstrap 3's btn-group-justified to Bootstrap 4 using scss (sass)

_button-groups.scss

// Justified button groups - table
// ----------------------

.btn-group-justified {
  display: table;
  width: 100%;
  table-layout: fixed;
  border-collapse: separate;
  .btn,
  .btn-group {
    float: none;
    display: table-cell;
    width: 1%;
    .btn {
      width: 100%;
    }
    .dropdown-menu {
      left: auto;
    }
  }
}

// Justified button groups - flexbox
// ----------------------

.btn-group-justified {
  display: flex;
  width: 100%;
  .btn,
  .btn-group {
    flex: 1;
    .btn {
      width: 100%;
    }
    .dropdown-menu {
      left: auto;
    }
  }
}