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| <div style="margin-left: 0px;"> The <b>BOOST_PP_IS_BEGIN_PAREN</b>S |
| determines whether the input starts with a set of parenthesis.</div> |
| <h4>Usage</h4> |
| <div class="code"> <b>BOOST_PP_IS_BEGIN_PARENS</b>(...) <a href="../topics/variadic_macros.html#VNotation" |
| target="_self"><sup>(v)</sup></a></div> |
| <h4>Arguments</h4> |
| <h4> ... <span style="font-weight: normal;"> |
| The input as variadic data.</span></h4> |
| <h4>Remarks</h4> |
| <div> If the input input begins with a parenthesis, with any data within |
| that parenthesis, the macro returns 1, otherwise it returns 0. Data may |
| follow the beginning parenthesis and the macro still will return 1.<br> |
| <br> |
| For Visual Studio 2005 ( VC8 ) the input data must be a single parameter |
| else a compilation error will occur.</div> |
| <h4>See Also</h4> |
| <ul> |
| <li><a href="remove_parens.html">BOOST_PP_REMOVE_PARENS</a></li> |
| </ul> |
| <h4>Requirements</h4> |
| <div> <b>Header:</b> <a href="../headers/punctuation/is_begin_parens.html"><boost/preprocessor/punctuation/is_begin_parens.hpp></a> |
| </div> |
| <h4>Sample Code</h4> |
| <div> |
| <pre>#include <<a href="../headers/punctuation/is_begin_parens.html">boost/preprocessor/punctuation/is_begin_parens.hpp</a>> |
| |
| #define VARDATA more_data , more_params<br>#define VARDATAP ( data ) more_data , more_params<br>#define DATA data<br>#define DATAP ( data ) more_data<br> |
| BOOST_PP_IS_BEGIN_PARENS(VARDATA) // expands to 0, compiler error with VC8 |
| BOOST_PP_IS_BEGIN_PARENS(VARDATAP) // expands to 1, compiler error with VC8<br><br>BOOST_PP_IS_BEGIN_PARENS(DATA) // expands to 0 |
| BOOST_PP_IS_BEGIN_PARENS(DATAP) // expands to 1<br><br>BOOST_PP_IS_BEGIN_PARENS() // expands to 0<br> |
| </pre></div> |
| <hr size="1"> |
| <div style="margin-left: 0px;"> <i>© Copyright Edward Diener 2014</i> </div> |
| <div style="margin-left: 0px;"> |
| <p><small>Distributed under the Boost Software License, Version 1.0. (See |
| accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> |
| or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> |
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