r">'a</span> <span>&#45;&gt;</span> <span class="type-var">'b</span>)</span> <a href="index.html#type-result">result</a></span></code></dt><dt class="spec value" id="val-foreign_value"><a href="#val-foreign_value" class="anchor"></a><code><span class="keyword">val</span> foreign_value : string <span>&#45;&gt;</span> <span><span class="type-var">'a</span> <a href="../index.html#type-typ">typ</a></span> <span>&#45;&gt;</span> <span><span><span class="type-var">'a</span> <a href="../index.html#type-ptr">ptr</a