Bootstrap3 Fixed Width Columns mixin

bootstrap3-fixed-width-columns-mixins.scss

// demo: http://codepen.io/JoelStransky/pen/VKPVAG
// breakpoint list ('column type', 'screen breakpoint', 'container width @ break point')
$breakpoints: ( ('xs', $screen-xs, $screen-xs), ('sm', $screen-sm, $container-sm), ('md', $screen-md, $container-md), ('lg', $screen-lg, $container-lg) );

@mixin make-fixed-grid() {
  @each $item in $breakpoints {
    @media (min-width: #{nth($item, 2)} ) {
      // background: red;
      @include make-fixed-grid-columns( $grid-columns, nth($item, 1), width, nth($item, 3) );
    }
  }
}

@mixin make-fixed-grid-columns($columns, $class, $type, $break) {
  @for $i from 0 through $columns {
    @include calc-fixed-column-width($i, $class, $type, $break);
  }
}

@mixin calc-fixed-column-width($index, $class, $type, $break) {
  @if ($type == width) and ($index > 0) {
    .col-#{$class}-fixed-#{$index} {
      width: (($index / $grid-columns) * $break) - $grid-gutter-width;
    }
  }
}

// optional, use this to inject fixed widths to any class
@mixin make-fixed-widths( $class ) {
  @each $item in $breakpoints {
    @for $i from 1 through $grid-columns {
      @include make-fixed-width(nth($item, 1), $i, $class);
    }
  }
}

@mixin make-fixed-width($size, $index, $class ) {
  #{$class} {
    .col-#{$size}-#{$index} & {
      @extend .col-#{$size}-fixed-#{$index};
    }
  }
}