https://svn.boost.org/trac10/ticket/12715 <p> Nested usage of BOOST_FOREACH issues the warnings: </p> <ul><li>warning C4456: declaration of '_foreach_col' hides previous local declaration </li><li>warning C4456: declaration of '_foreach_cur' hides previous local declaration </li><li>warning C4456: declaration of '_foreach_end' hides previous local declaration </li><li>warning C4456: declaration of '_foreach_continue' hides previous local declaration </li></ul><p> Example code: </p> <pre class="wiki">#include &lt;boost/foreach.hpp&gt; int main() { std::vector&lt;int&gt; iv(10); BOOST_FOREACH(int &amp;i, iv) { std::vector&lt;int&gt; iv2(10); BOOST_FOREACH(int &amp;i2, iv2) { i2 = 2; } i = 1; } } </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12715 Trac 1.4.3