| Brian Silverman | f27e085 | 2018-08-04 23:56:45 -0700 | [diff] [blame^] | 1 | <html> |
| 2 | <head> |
| 3 | <title>BOOST_PP_DEDUCE_Z</title> |
| 4 | <link rel="stylesheet" type="text/css" href="../styles.css"> |
| 5 | </head> |
| 6 | <body> |
| 7 | <div style="margin-left: 0px;"> |
| 8 | The <b>BOOST_PP_DEDUCE_Z</b> macro manually deduces the state of the <b>BOOST_PP_REPEAT</b> construct. |
| 9 | </div> |
| 10 | <h4>Usage</h4> |
| 11 | <div class="code"> |
| 12 | <b>BOOST_PP_DEDUCE_Z</b>() |
| 13 | </div> |
| 14 | <h4>Remarks</h4> |
| 15 | <div> |
| 16 | This macro is intended to avoid the use of <i>automatic-recursion</i> at deep expansion depths. |
| 17 | <i>Automatic-recursion</i> at such depths can be inefficient on some preprocessors. |
| 18 | It is not intended to be used directly with the invocation of macros with a <b>_Z</b> suffix such as: |
| 19 | <div> |
| 20 | <b>BOOST_PP_ENUM_PARAMS_Z</b>(<b>BOOST_PP_DEDUCE_Z</b>(), (a, (b, (c, <b>BOOST_PP_NIL</b>)))) |
| 21 | </div> |
| 22 | If it is used in this context, the <b>_Z</b> macro will fail. |
| 23 | The <b>_Z</b> macros directly concatenate to the <i>r</i> parameter that is passed to them, |
| 24 | which would prevent <b>BOOST_PP_DEDUCE_Z</b>() from expanding. |
| 25 | Furthermore, it is pointless to use this macro in a situation such as this |
| 26 | because it would already be too late to gain any efficiency. |
| 27 | </div> |
| 28 | <h4>See Also</h4> |
| 29 | <ul> |
| 30 | <li><a href="repeat.html">BOOST_PP_REPEAT</a></li> |
| 31 | </ul> |
| 32 | <h4>Requirements</h4> |
| 33 | <div> |
| 34 | <b>Header:</b> <a href="../headers/repetition/deduce_z.html"><boost/preprocessor/repetition/deduce_z.hpp></a> |
| 35 | </div> |
| 36 | <hr size="1"> |
| 37 | <div style="margin-left: 0px;"> |
| 38 | <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> |
| 39 | </br><i>© Copyright Paul Mensonides 2002</i> |
| 40 | </div> |
| 41 | <div style="margin-left: 0px;"> |
| 42 | <p><small>Distributed under the Boost Software License, Version 1.0. (See |
| 43 | accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or |
| 44 | copy at <a href= |
| 45 | "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> |
| 46 | </div> |
| 47 | </body> |
| 48 | </html> |