lass="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../tribool/reference.html#header.boost.logic.tribool_io_hpp" title="Header &lt;boost/logic/tribool_io.hpp&gt;">boost/logic/tribool_io.hpp</a>&gt;

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<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</