o equivalent node.</p>
<p><span class="bold"><strong>Returns</strong></span>: If there is an equivalent value returns a pair containing a node_ptr to the already present node and false. If there is not equivalent key can be inserted returns true in the returned pair's boolean and fills "commit_data" that is meant to be used with the "insert_commit" function to achieve a constant-time insertion function.</p>
<p><span class="bold"><strong>Complexity</strong></span>: Average complexity is at most logarithmic.<