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    copied!<p>Somewhat clearer (???) with a bit of boost preprocessing. </p> <p>You define your enums by a sequence </p> <pre><code>#define CAPI_SUBTYPE_E_Sequence \ (CAPI_SUBTYPE_NULL)(0) \ (CAPI_SUBTYPE_DIAG_DFD)(1) ... </code></pre> <p>then you can automate (through macros) the declaration of the enum, </p> <pre><code>DECL_ENUM(CAPI_SUBTYPE_E) ; </code></pre> <p>the table that indexes it</p> <pre><code>DECL_ENUM_TABLE(CAPI_SUBTYPE_E); </code></pre> <p>the number of enums / size of the table</p> <pre><code>ENUM_SIZE(CAPI_SUBTYPE_E) </code></pre> <p>and access to it:</p> <pre><code>ITER_ENUM_i(i,CAPI_SUBTYPE_E) </code></pre> <p>Here is the full text.</p> <pre><code>#include &lt;boost/preprocessor.hpp&gt; // define your enum as (name)(value) sequence #define CAPI_SUBTYPE_E_Sequence \ (CAPI_SUBTYPE_NULL)(0) /* Null subtype. */ \ (CAPI_SUBTYPE_DIAG_DFD)(1) /* Data Flow diag. */ \ (CAPI_SUBTYPE_DIAG_ERD)(2) /* Entity-Relationship diag. */ \ (CAPI_SUBTYPE_DIAG_DSD)(5) /* Data Structure diag. */ \ (CAPI_SUBTYPE_DD_ALL)(13) /* DD Entries (All). */ // # enums #define ENUM_SIZE(name) \ BOOST_PP_DIV(BOOST_PP_SEQ_SIZE(BOOST_PP_CAT(name,_Sequence)),2) #define ENUM_NAME_N(N,seq) BOOST_PP_SEQ_ELEM(BOOST_PP_MUL(N,2),seq) #define ENUM_VALUE_N(N,seq) BOOST_PP_SEQ_ELEM(BOOST_PP_INC(BOOST_PP_MUL(N,2)),seq) // declare Nth enum #define DECL_ENUM_N(Z,N,seq) \ BOOST_PP_COMMA_IF(N) ENUM_NAME_N(N,seq) = ENUM_VALUE_N(N,seq) // declare whole enum #define DECL_ENUM(name) \ typedef enum { \ BOOST_PP_REPEAT( ENUM_SIZE(name) , DECL_ENUM_N , BOOST_PP_CAT(name,_Sequence) ) \ } name DECL_ENUM(CAPI_SUBTYPE_E) ; // declare Nth enum value #define DECL_ENUM_TABLE_N(Z,N,seq) \ BOOST_PP_COMMA_IF(N) ENUM_NAME_N(N,seq) // declare table #define DECL_ENUM_TABLE(name) \ static const name BOOST_PP_CAT(name,_Table) [ENUM_SIZE(name)] = { \ BOOST_PP_REPEAT( ENUM_SIZE(name) , DECL_ENUM_TABLE_N , BOOST_PP_CAT(name,_Sequence) ) \ } DECL_ENUM_TABLE(CAPI_SUBTYPE_E); #define ITER_ENUM_i(i,name) BOOST_PP_CAT(name,_Table) [i] // demo // outputs : [0:0] [1:1] [2:2] [3:5] [4:13] #include &lt;iostream&gt; int main() { for (int i=0; i&lt;ENUM_SIZE(CAPI_SUBTYPE_E) ; i++) std::cout &lt;&lt; "[" &lt;&lt; i &lt;&lt; ":" &lt;&lt; ITER_ENUM_i(i,CAPI_SUBTYPE_E) &lt;&lt; "] "; return 0; } // bonus : check enums are unique and in-order #include &lt;boost/preprocessor/stringize.hpp&gt; #include &lt;boost/static_assert.hpp&gt; #define CHECK_ENUM_N(Z,N,seq) \ BOOST_PP_IF( N , \ BOOST_STATIC_ASSERT_MSG( \ ENUM_VALUE_N(BOOST_PP_DEC(N),seq) &lt; ENUM_VALUE_N(N,seq) , \ BOOST_PP_STRINGIZE( ENUM_NAME_N(BOOST_PP_DEC(N),seq) ) " not &lt; " BOOST_PP_STRINGIZE( ENUM_NAME_N(N,seq) ) ) \ , ) ; #define CHECK_ENUM(name) \ namespace { void BOOST_PP_CAT(check_enum_,name) () { \ BOOST_PP_REPEAT( ENUM_SIZE(name) , CHECK_ENUM_N , BOOST_PP_CAT(name,_Sequence) ) } } // enum OK CHECK_ENUM(CAPI_SUBTYPE_E) #define Bad_Enum_Sequence \ (one)(1)\ (five)(5)\ (seven)(7)\ (three)(3) // enum not OK : enum_iter.cpp(81): error C2338: seven not &lt; three CHECK_ENUM(Bad_Enum) </code></pre>
 

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