The BOOST_PP_ENUM_TRAILING_z macro represents a reentry into the BOOST_PP_ENUM_TRAILING repetition construct.
Usage
BOOST_PP_ENUM_TRAILING_ ## z(count, macro, data)
Arguments
- z
-
The next available BOOST_PP_REPEAT dimension.
- count
-
The number of repetitious calls to macro.
Valid values range from 0 to BOOST_PP_LIMIT_REPEAT.
- macro
-
A ternary operation of the form macro(z, n, data).
This macro is expanded by BOOST_PP_ENUM with the next available repetition depth,
the current repetition number, and the auxiliary data argument.
- data
-
Auxiliary data passed to macro.
Remarks
This macro expands to the sequence:
, macro(z, 0, data), macro(z, 1, data), ... macro(z, count - 1, data)
At certain times, it may be necessary to perform the concatenation with
BOOST_PP_CAT rather than the preprocessor token-pasting operator.
This happens when the
z value is a macro invocation itself.
It needs a delay to allow it to expand.
The syntax in such a scenario becomes:
BOOST_PP_CAT(BOOST_PP_ENUM_TRAILING_, z)(count, macro, data)
See Also
Requirements
Sample Code
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_trailing.hpp>
#define TEXT(z, n, text) text
#define TTP(z, n, _) \
template< \
class BOOST_PP_ENUM_TRAILING_ ## z(n, TEXT, class) \
> \
class T ## n \
/**/
BOOST_PP_ENUM(3, TTP, nil)
/*
expands to...
template<class> class T0,
template<class, class> class T1,
template<class, class, class> class T2
*/