The BOOST_PP_ENUM_SHIFTED macro generates a comma-separated, shifted list.
Usage
BOOST_PP_ENUM_SHIFTED(count, macro, data)
Arguments
- 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_SHIFTED 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 comma-separated sequence:
macro(z, 1, data), ... macro(z, count - 1, data)
The z value that is passed to macro represents the next available repetition dimension.
Other macros that have _Z suffix variants internally use BOOST_PP_REPEAT--for example, BOOST_PP_ENUM_PARAMS and BOOST_PP_ENUM_PARAMS_Z.
Using these _Z versions is not strictly necessary, but passing the z value (that is passed to macro) to these macros allows them to reenter BOOST_PP_REPEAT with maximum efficiency.
To directly use this z value, rather than simply passing it to another macro, see BOOST_PP_ENUM_SHIFTED_z.
Previously, this macro could not be used recursively inside BOOST_PP_REPEAT.
This limitation no longer exists, as the library can automatically detect the next available repetition depth.
See Also
Requirements
Sample Code
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_shifted.hpp>
#define TYPE(z, n, type) type
BOOST_PP_ENUM(5, TYPE, int) // expands to int, int, int, int, int
BOOST_PP_ENUM_SHIFTED(5, TYPE, int) // expands to int, int, int, int