----- Original Message ----- From: "Joel de Guzman" To: Sent: Monday, January 25, 2010 9:38 AM Subject: Re: [Boost-users] BOOST_FUSION_ADAPT_STRUCT: non intrusive macro, get a fusion sequence of struct member types and member names

On 1/24/2010 8:29 PM, Hicham Mouline wrote:

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Hello, I am aware that it is planned to implement metafunctions that returned the list of member types of a struct, as well as members names, as fusion/mpl sequences. The macro uses some PP magic. My project has progressed that I think I need this feature to proceed. I may try my hand at implementing these features... Which files in boost/fusion are involved in the implementation of the macro?

See boost/fusion/adapted/struct. The member types are already provided through result_of::at_c. Of course (this is the kind of mistakes beginners do, not paying attention:-( )

The names are not (yet). Be warned, I have to insist on updating the docs too :-) Ahem ahem...

Do tell us your proposed interface. One way is to return a fusion sequence of as many "const char*" as there are members in the struct, so the types are "const char*" and the runtime values are the member names. That wouldn't suit my case as I wouldn't be able to generate the spirit grammar wiht PP at compile-time.

How can the member names be stored in the type information of the fusion /mpl sequence as const char* ?

From what I understand, you can only have template non-type arguments that have an external linkage. Hmmm, I don't know.

Docs, absolutely, glad to make any contribution. I need to read up about quickbook, right? regards,

struct_member_name_at/at_c< index, struct_adapted_as_fusion_sequence > hmm, it's the same problem with the const char*

Is there no way to provide the member names at compile time? There must be something obvious and I am just not seeing it. name will obviously be char* and you can't have that in a template

Hicham Mouline wrote: parameter. Best shot is to generate types with name looking like member name. -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

----- Original Message ----- From: "Joel de Guzman" To: Sent: Monday, January 25, 2010 8:55 PM Subject: Re: [Boost-users] BOOST_FUSION_ADAPT_STRUCT: non intrusive macro, get a fusion sequence of struct member types and member names

On 1/25/2010 6:54 PM, joel falcou wrote:

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struct_member_name_at/at_c< index, struct_adapted_as_fusion_sequence > hmm, it's the same problem with the const char*

Is there no way to provide the member names at compile time? There must be something obvious and I am just not seeing it. name will obviously be char* and you can't have that in a template

Hicham Mouline wrote: parameter. Best shot is to generate types with name looking like member name.

I think it should just be simple functions:

template char const* name_at_c(Sequence const& seq);

template char const* name_at(Sequence const& seq);

There should be a compile error if Sequence has no named members. Some types of sequences may implement it through a customization point (same scheme that at_c and friends use).

(http://tinyurl.com/yeafcol)

The function argument would not be necessary, wouldn't it? All the information is available in the type Sequence. template char const* name_at_c(); This would then be at runtime, not compile time?. rds,

----- Original Message ----- From: "Dominique Devienne" To: Sent: Tuesday, January 26, 2010 12:58 AM Subject: Re: [Boost-users] BOOST_FUSION_ADAPT_STRUCT: non intrusive macro,get a fusion sequence of struct member types and member names

On Mon, Jan 25, 2010 at 4:54 AM, joel falcou wrote:

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name will obviously be char* and you can't have that in a template parameter.

Unless using mpl::string, no? Not sure it's possible to generate mpl::string<'foob','ar'> from "foobar" passed to the macro though. --DD

Then we could have metafunctions template struct name_at_c { typedef <undefined> type; // this would be a mpl::string }; this would be at compile time. rds,