title: How can I make element in grow if there's no other siblings in it's .row?
body: <p>Consider this code: </p>
  
  <p><a href="https://codepen.io/Kezhich/pen/pXNevv" rel="nofollow noreferrer">https://codepen.io/Kezhich/pen/pXNevv</a></p>
  
  <p>Question: How can I make input-group grow up to full container's width if there's no round-button inside?</p>
  
  <p>Already tried flex-grow. Didn't work to me.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.btn_circle {
          width: 30px;
          height: 30px;
          text-align: center;
          padding: 6px 0;
          font-size: 12px;
          line-height: 1.428571429;
          border-radius: 15px;
          min-width: 30px;
          min-height: 30px;
      }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/&gt;
      &lt;div class="jumbotron shadow py-2 px-3"&gt;
        &lt;div class="row col-12 px-0 mb-2"&gt;
          &lt;div class="col-11"&gt;
            &lt;div class="input-group input-group-sm"&gt;
              &lt;div class="input-group-prepend"&gt;
                &lt;span class="input-group-text form__prepend"&gt;
                  &lt;b&gt;№1&lt;/b&gt;
                &lt;/span&gt;
              &lt;/div&gt;
              &lt;input type="text" class="form-control form-control-sm" placeholder="blah blah blah" /&gt;
            &lt;/div&gt;
          &lt;/div&gt;
          &lt;div class="col-1 pr-0 d-flex justify-content-end form__delivery__delete"&gt;
            &lt;button class="btn btn-primary btn_circle"&gt;
              &lt;i class="fas fa-times"&gt;&lt;/i&gt;
            &lt;/button&gt;
          &lt;/div&gt;
        &lt;/div&gt;
      &lt;/div&gt;</code></pre>
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