The BOOST_PP_COMMA_IF macro conditionally expands to a comma.
Usage
BOOST_PP_COMMA_IF(cond)
Arguments
- cond
-
The condition that determines if a the macro expands to a comma or nothing.
Valid values range from 0 to BOOST_PP_LIMIT_MAG.
Remarks
If cond expands to 0, this macro expands to nothing.
Otherwise, it expands to a comma.
The preprocessor interprets commas as argument separators in macro invocations.
Because of this, commas require special handling.
See Also
Requirements
#include <boost/preprocessor/punctuation/comma_if.hpp>
#include <boost/preprocessor/repetition/repeat.hpp>
#define MACRO(z, n, text) BOOST_PP_COMMA_IF(n) text
BOOST_PP_REPEAT(3, MACRO, class) // expands to class, class, class