le>
  body {
    margin: 0px;
    line-height: 1;
  }

  #too-wide {
    display: inline-block;
    height: 20px;
    width: 250px;
    background: blue;
  }

  #shape {
    width: 100px;
    height: 100px;
    float: left;
    shape-outside: polygon(0px 0px, 100px 0px, 0px 100px);
  }
</style>

<div style="width: 300px; height: 100px;">
<div id="shape"></div>
<span id="too-wide"></span>
<div>
