title: Why "checked" property and v-model can not be used together in Vue?
body: <p>I'd like to know why "checked" property in a series of input checkbox elements become unaccessible if v-model is used in these elements in Vue.</p>
  
  <p>Recently I tried to add CheckAll functionality to a list of items.
  Without v-model it's trivial:</p>
  
  <pre><code>&lt;input type="checkbox" v-model="checkAll"&gt;
  &lt;div class="list"&gt;
    &lt;input v-for="item in items" :value="item.id" type="checkbox" :checked="checkAll"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>But if I add v-model "toRemove" to each item in order to get an array of checked items, checkAll checkbox stops working:</p>
  
  <pre><code>&lt;input type="checkbox" v-model="checkAll"&gt;
  &lt;div class="list"&gt;
    &lt;input v-for="item in items" :value="item.id" type="checkbox" :checked="checkAll" v-model="toRemove"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>It's interesting that "disable" property works well with V-model in a similar manner:</p>
  
  <pre><code>&lt;input type="checkbox" v-model="checkAll"&gt;
  &lt;div class="list"&gt;
    &lt;input v-for="item in items" :value="item.id" type="checkbox" :disabled="checkAll" v-model="toRemove"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I wonder why Vue does not allow both checkAll and an array of checked items via v-model at the same time.</p>