Files
boost_preprocessor/include/boost/preprocessor/identity.hpp
2001-12-03 21:11:11 +00:00

45 lines
1.1 KiB
C++

#ifndef BOOST_PREPROCESSOR_IDENTITY_HPP
#define BOOST_PREPROCESSOR_IDENTITY_HPP
// Copyright (C) 2001
// Housemarque Oy
// http://www.housemarque.com
//
// Permission to copy, use, modify, sell and distribute this software is
// granted provided this copyright notice appears in all copies. This
// software is provided "as is" without express or implied warranty, and
// with no claim as to its suitability for any purpose.
// See http://www.boost.org for most recent version.
/*! \file
<a href="../../../../boost/preprocessor/identity.hpp">Click here to see the header.</a>
*/
#ifndef BOOST_PREPROCESSOR_EMPTY_HPP
# include <boost/preprocessor/empty.hpp>
#endif
//! Expands to X once invoked.
/*!
Designed to be used with BOOST_PREPROCESSOR_IF(), when one of the clauses need to be invoked.
Example:
<PRE>\verbatim
BOOST_PREPROCESSOR_IDENTITY(X)()
// ^^ NOTE!
\endverbatim</PRE>
The above expands to:
<PRE>\verbatim
X
\endverbatim</PRE>
NOTE: If BOOST_PREPROCESSOR_IDENTITY() is not invoked, the expansion will not be usable.
*/
#define BOOST_PREPROCESSOR_IDENTITY(X) X BOOST_PREPROCESSOR_EMPTY
#endif