The BOOST_PP_SET_ELEM macro extracts an element from a set.

Usage

BOOST_PP_SET_ELEM(i, list)

Arguments

i
The zero-based index of the element to be extracted.
set
The set from which an element is to be extracted.

Remarks

The index i must be in the range of 0 to BOOST_PP_SET_SIZE(set) - 1.

Requirements

Header:  <boost/preprocessor/set/elem.hpp>

Sample Code

#include <boost/preprocessor/set/elem.hpp>

BOOST_PP_SET_ELEM(1, (a)(b)(c)) // expands to b

#define SET \
   (0)(1)(2)(3)(4)(5)(6)(7)(8)(9) \
   (10)(11)(12)(13)(14)(15)(16)(17)(18)(19) \
   (20)(21)(22)(23)(24)(25)(26)(27)(28)(29) \
   (30)(31)(32)(33)(34)(35)(36)(37)(38)(39) \
   (40)(41)(42)(43)(44)(45)(46)(47)(48)(49) \
   (50)(51)(52)(53)(54)(55)(56)(57)(58)(59) \
   (60)(61)(62)(63)(64)(65)(66)(67)(68)(69) \
   (70)(71)(72)(73)(74)(75)(76)(77)(78)(79) \
   (80)(81)(82)(83)(84)(85)(86)(87)(88)(89) \
   (90)(91)(92)(93)(94)(95)(96)(97)(98)(99) \
   /**/

BOOST_PP_SET_ELEM(88, SET) // expands to 88