The BOOST_PP_EXPR_IIF macro expands to its second argument if its first argument is 1 and expands to nothing if its first argument is 0.

Usage

BOOST_PP_EXPR_IIF(bit, expr)

Arguments

bit
The condition that determines if the result is expr or nothing.  This value must expand to 0 or 1.
expr
The result of the expansion if bit is 1.

Remarks

This macro does not perform a boolean conversion on its first argument.  If that conversion is necessary, use BOOST_PP_EXPR_IF instead.

See Also

Requirements

Header:  <boost/preprocessor/control/expr_iif.hpp>

Sample Code

#include <boost/preprocessor/comparison/and.hpp>
#include <boost/preprocessor/control/expr_iif.hpp>

#define INSERT_AND(p, q, text) /* ... */ \
   BOOST_PP_EXPR_IIF(                    \
      BOOST_PP_AND(p, q),                \
      text                               \
   )                                     \
   /**/

INSERT_AND(2, 3, abc) // expands to abc
INSERT_AND(0, 7, xyz) // expands to nothing