sions of the underlying type R.
        Operations which are legal on values of type R such as +, -, ... are
        also legal on values of <a class="link" href="checked_result.html" title="checked_result&lt;R&gt;"><code class="computeroutput">checked_result&lt;R&gt;</code></a>.
        The difference is that the latter can record operation failures and
        propagate such failures to subsequent operations.<a class="link" href="checked_result.html" title="checked_result&lt;R&gt;"><code class="computerou