an <code>EP</code>.
Similarly to <code>result</code>, <code>EC</code> defaults to <code>std::error_code</code>/<code>boost::system::error_code</code>, and <code>EP</code> defaults to <code>std::exception_ptr</code>/<code>boost::exception_ptr</code>.</p>

<p>The distinction is made into two types, <code>EC</code> and <code>EP</code>:</p>

<ul>
<li><code>EC</code> represents a <em>recoverable</em> failure from a lower-layer function, perhaps which was returned through <a href="../../reference/aliases/result.h