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

- BOOST_PP_EXPR_IF
- BOOST_PP_LIMIT_MAG

#### Requirements

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

#### Sample Code

    #include <boost/preprocessor/logical/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