class="highlight swift"><code><span class="kd">public</span> <span class="kd">func</span> <span class="nf">formConstrain</span><span class="p">(</span><span class="nv">sourceRect</span><span class="p">:</span> <span class="k">inout</span> <span class="kt"><a href="../Typealiases.html#/s:8CGLayout6CGRecta">CGRect</a></span><span class="p">,</span> <span class="n">by</span> <span class="nv">rect</span><span class="p">:</span> <span class="kt"><a href="../Typealiases.html#/s:8CGLayout6CGRecta">CGRect</a></span