| 1 | <html> |
|---|
| 2 | <head> |
|---|
| 3 | <title>BOOST_PP_ASSERT</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_ASSERT</b> macro conditionally causes a preprocessing error. |
|---|
| 9 | </div> |
|---|
| 10 | <h4>Usage</h4> |
|---|
| 11 | <div class="code"> |
|---|
| 12 | <b>BOOST_PP_ASSERT</b>(<i>cond</i>) |
|---|
| 13 | </div> |
|---|
| 14 | <h4>Arguments</h4> |
|---|
| 15 | <dl> |
|---|
| 16 | <dt>cond</dt> |
|---|
| 17 | <dd> |
|---|
| 18 | A condition that determines whether an assertion occurs. |
|---|
| 19 | Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_MAG</b>. |
|---|
| 20 | </dd> |
|---|
| 21 | </dl> |
|---|
| 22 | <h4>Remarks</h4> |
|---|
| 23 | <div> |
|---|
| 24 | If <i>cond</i> expands to <i>0</i>, this macro causes a preprocessing error. |
|---|
| 25 | Otherwise, it expands to nothing. |
|---|
| 26 | </div> |
|---|
| 27 | <h4>See Also</h4> |
|---|
| 28 | <ul> |
|---|
| 29 | <li><a href="assert_msg.html">BOOST_PP_ASSERT_MSG</a></li> |
|---|
| 30 | <li><a href="limit_mag.html">BOOST_PP_LIMIT_MAG</a></li> |
|---|
| 31 | </ul> |
|---|
| 32 | <h4>Requirements</h4> |
|---|
| 33 | <div> |
|---|
| 34 | <b>Header:</b> <a href="../headers/debug/assert.html"><boost/preprocessor/debug/assert.hpp></a> |
|---|
| 35 | </div> |
|---|
| 36 | <h4>Sample Code</h4> |
|---|
| 37 | <div><pre> |
|---|
| 38 | #include <<a href="../headers/cat.html">boost/preprocessor/cat.hpp</a>> |
|---|
| 39 | #include <<a href="../headers/debug/assert.html">boost/preprocessor/debug/assert.hpp</a>> |
|---|
| 40 | #include <<a href="../headers/logical/bitnor.html">boost/preprocessor/logical/bitnor.hpp</a>> |
|---|
| 41 | #include <<a href="../headers/logical/compl.html">boost/preprocessor/logical/compl.hpp</a>> |
|---|
| 42 | |
|---|
| 43 | // The is BOOST_PP_IS_NULLARY macro is not part of |
|---|
| 44 | // the public interface of the library because it |
|---|
| 45 | // doesn't work on Borland preprocessors. It is |
|---|
| 46 | // only used here to illustrate assertions. In |
|---|
| 47 | // effect, it detects whether an argument is empty |
|---|
| 48 | // parenthesis or some text. |
|---|
| 49 | |
|---|
| 50 | #include <boost/preprocessor/detail/is_nullary.hpp> |
|---|
| 51 | |
|---|
| 52 | #define IS_EDISON_DESIGN_GROUP() \ |
|---|
| 53 | <a href="compl.html">BOOST_PP_COMPL</a>( \ |
|---|
| 54 | BOOST_PP_IS_NULLARY( \ |
|---|
| 55 | <a href="cat.html">BOOST_PP_CAT</a>(IS_EDG_CHECK, __EDG_VERSION) \ |
|---|
| 56 | ) \ |
|---|
| 57 | ) \ |
|---|
| 58 | /**/ |
|---|
| 59 | #define IS_EDG_CHECK__EDG_VERSION () |
|---|
| 60 | |
|---|
| 61 | #define IS_METROWERKS() \ |
|---|
| 62 | <a href="compl.html">BOOST_PP_COMPL</a>( \ |
|---|
| 63 | BOOST_PP_IS_NULLARY( \ |
|---|
| 64 | <a href="cat.html">BOOST_PP_CAT</a>(IS_MWERKS_CHECK, __MWERKS__) \ |
|---|
| 65 | ) \ |
|---|
| 66 | ) \ |
|---|
| 67 | /**/ |
|---|
| 68 | #define IS_MWERKS_CHECK__MWERKS__ () |
|---|
| 69 | |
|---|
| 70 | #define IS_MICROSOFT() \ |
|---|
| 71 | <a href="bitnor.html">BOOST_PP_BITNOR</a>( \ |
|---|
| 72 | IS_MICROSOFT_ROOT(), \ |
|---|
| 73 | IS_EDISON_DESIGN_GROUP() \ |
|---|
| 74 | ) \ |
|---|
| 75 | /**/ |
|---|
| 76 | #define IS_MICROSOFT_ROOT() \ |
|---|
| 77 | BOOST_PP_IS_NULLARY( \ |
|---|
| 78 | <a href="cat.html">BOOST_PP_CAT</a>(IS_MSVC_CHECK, _MSC_VER) \ |
|---|
| 79 | ) \ |
|---|
| 80 | /**/ |
|---|
| 81 | #define IS_MSVC_CHECK_MS_VER () |
|---|
| 82 | |
|---|
| 83 | // this macro doesn't work on EDG... |
|---|
| 84 | // (this is just an example) |
|---|
| 85 | |
|---|
| 86 | #define MACRO(n) \ |
|---|
| 87 | <a href="cat.html">BOOST_PP_CAT</a>( \ |
|---|
| 88 | MACRO_, \ |
|---|
| 89 | IS_EDISON_DESIGN_GROUP() \ |
|---|
| 90 | )(n) \ |
|---|
| 91 | /**/ |
|---|
| 92 | |
|---|
| 93 | #define MACRO_1(n) \ |
|---|
| 94 | <a href="assert.html">BOOST_PP_ASSERT</a>(0) \ |
|---|
| 95 | "Edison Design Group is not supported" \ |
|---|
| 96 | /**/ |
|---|
| 97 | |
|---|
| 98 | #define MACRO_0(n) normal mode: n |
|---|
| 99 | |
|---|
| 100 | MACRO(10) |
|---|
| 101 | </pre></div> |
|---|
| 102 | </body> |
|---|
| 103 | </html> |
|---|
