type">char</span>* value, <span class="keywordtype">int</span> overwrite);</div><div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;</div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;    BOOST_NOWIDE_DECL <span class="keywordtype">int</span> <a class="code" href="namespaceboost_1_1nowide.html#add09e67957a286d27f6f703ce1bc775c">unsetenv</a>(<span class="keyword">const</span> <span class="keywordtype">char</span>* key);</div><div class="line"><a name=