feat: col-*-0 means `display: none`

components/layout/col.jsx

@@ -31,7 +31,7 @@ const Col = React.createClass({
       }
       sizeClassObj = {
         ...sizeClassObj,
-        [`col-${size}-${sizeProps.span}`]: sizeProps.span,
+        [`col-${size}-${sizeProps.span}`]: sizeProps.span !== undefined,
         [`col-${size}-order-${sizeProps.order}`]: sizeProps.order,
         [`col-${size}-offset-${sizeProps.offset}`]: sizeProps.offset,
         [`col-${size}-push-${sizeProps.push}`]: sizeProps.push,
@@ -39,7 +39,7 @@ const Col = React.createClass({
       };
     });
     const classes = classNames({
-      [`col-${span}`]: span,
+      [`col-${span}`]: span !== undefined,
       [`col-order-${order}`]: order,
       [`col-offset-${offset}`]: offset,
       [`col-push-${push}`]: push,

components/layout/index.md

@@ -99,7 +99,7 @@ Ant Design 的布局组件若不能满足你的需求，你也可以直接使用
 
 | 成员        | 说明             | 类型               | 默认值       |
 |------------|-----------------|--------------------|-------------|
-| span     | 栅格占位格数   | number | 0        |
+| span     | 栅格占位格数，为 0 时相当于 `display: none`   | number | 无        |
 | order     | 栅格顺序，`flex` 布局模式下有效   | number | 0        |
 | offset     | 栅格左侧的间隔格数，间隔内不可以有栅格  | number | 0        |
 | push     | 栅格向右移动格数   | number | 0        |

style/mixins/grid.less

@@ -32,6 +32,7 @@
 
 .loop-grid-columns(@index, @class) when (@index > 0) {
   .col@{class}-@{index} {
+    display: block;
     width: percentage((@index / @grid-columns));
   }
   .col@{class}-push-@{index} {
@@ -49,7 +50,10 @@
   .loop-grid-columns((@index - 1), @class);
 }
 
-.loop-grid-columns(@index) when (@index = 0) {
+.loop-grid-columns(@index, @class) when (@index = 0) {
+  .col@{class}-@{index} {
+    display: none;
+  }
   .col-push-@{index} {
     left: auto;
   }