<html> <head> <title>BOOST_PP_DEDUCE_R</title> <link rel="stylesheet" type="text/css" href="../styles.css"> </head> <body> <div style="margin-left: 0px;"> The <b>BOOST_PP_DEDUCE_R</b> macro manually deduces the state of the <b>BOOST_PP_FOR</b> construct. </div> <h4>Usage</h4> <div class="code"> <b>BOOST_PP_DEDUCE_R</b>() </div> <h4>Remarks</h4> <div> This macro is intended to avoid the use of <i>automatic-recursion</i> at deep expansion depths. <i>Automatic-recursion</i> at such depths can be inefficient on some preprocessors. It is not intended to be used directly with the invocation of macros with a <b>_R</b> suffix such as: <div> <b>BOOST_PP_LIST_ENUM_R</b>(<b>BOOST_PP_DEDUCE_R</b>(), (a, (b, (c, <b>BOOST_PP_NIL</b>)))) </div> If it is used in this context, the <b>_R</b> macro will fail. The <b>_R</b> macros directly concatenate to the <i>r</i> parameter that is passed to them, which would prevent <b>BOOST_PP_DEDUCE_R</b>() from expanding. Furthermore, it is pointless to use this macro in a situation such as this because it would already be too late to gain any efficiency. </div> <h4>See Also</h4> <ul> <li><a href="for.html">BOOST_PP_FOR</a></li> </ul> <h4>Requirements</h4> <div> <b>Header:</b> <a href="../headers/repetition/deduce_r.hpp.html"><boost/preprocessor/repetition/deduce_r.hpp></a> </div> </body> </html>
