Mark Schlegel <moschleg <at> verizon.net> writes: [...]
template<typename KEYT, typename T> class AgedMap { public: typedef multi_index_container< MapEntry<KEYT, T>, indexed_by< ordered_unique< tag<keytag>, BOOST_MULTI_INDEX_MEMBER(MapEntry<KEYT,T>, KEYT, key) >, ordered_non_unique< tag<agetag>, BOOST_MULTI_INDEX_MEMBER(MapEntry<KEYT,T>, int, age) > > > AGEDMAPTYPE; }; [...] "error: macro "BOOST_MULTI_INDEX_MEMBER" passed 4 arguments, but takes just 3"
so gcc thinks it's parsing out 4 args and not three.
I then thought it was the typical macro problem with parsing so I put parens around the MapEntry first arguments to BOOST_MULTI_INDEX_MEMBER():
BOOST_MULTI_INDEX_MEMBER((MapEntry<KEYT,T>), KEYT, key) >,
This didn't help either, is it not allowed to exceed one template argument in an argument to BOOST_MULTI_INDEX_MEMBER() so for example MapEntry<T> is ok but MapEntry<KEYT,T> is not?
Hello Mark, The extra parens trick will or won't work depending on the context where the overparenthesized arg is expanded into --in this case you're out of luck. You've got several other options, among them the following: 1. You can use boost::multi_index::member<> directly; after all, BOOST_MULTI_INDEX_MEMBER is mainly provided as a workaround for some broken compilers (though its syntax is terser than using naked member<>): member<MapEntry<KEYT,T>, KET,&MapEntry<KEYT,T>::key> 2. Use a typedef so that the extra comma does not appear inside the macro: typedef MapEntry<KEYT,T> ValueType; ... BOOST_MULTI_INDEX_MEMBER(ValueType, KEYT, key) Hope this helps, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo