Re: [Boost-users] [multi-index] member arguments [Was: how to use in heritmember as index]

Filip Konvi?ka ha escrito:

...

If you're using Boost 1.34, then you can simply use

hashed_unique< tag<userid>, member >

Hi,

I'm just curious - is there a reason why "member" takes 3 template parameters, and not just one, like in

member<&Peer::userid>

? The first two types can be extracted from the member pointer, so I find this a bit redundant...

It certainly looks redundant, but it turns out you really cannot do what you propose: template<...> struct member; What should "..." look like? It's not a type parameter, but it cannot be made a non-type parameter either since we don't know the type of the pointer-to-member being passed... In decltype- (or typeof-) enabled compilers a terser syntax could be achieved by using some macro hackery: template struct member; #define MEMBER(PtrToMember) \ member So maybe when C++0x arrives we can take advantage of this. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo