Re: [boost] sqlpp11, 3rd iteration

On 2014-08-20 00:34, Adam Wulkiewicz wrote:

Roland Bock wrote:

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Ok AFAIU a struct like _member_t should define some convenient member variable for the user and must define operator() for the library. But the rest could be automatically generated, couldn't it? Why not just pass a list of templates of classes adapted to MemberType concept (defined operator()) into the table/column/etc.? I'm thinking about something like the code below. I don't know exactly what's required so this is just an example of a technique rather than a solution ready-to-use in sqlpp. The idea is good. For the columns, you will have to add a few more

On 2014-08-19 18:56, Adam Wulkiewicz wrote: parameters, e.g. the value_type (mandatory), can_be_null, must_not_insert, must_not_update, null_is_trivial, trivial_is_null, maybe as per your suggestion a default value or a function for producing it. That default stuff might be tough in such a design.

The additional traits would be a list of variadic template parameters. So if this list contained only one type, e.g. sqlpp::default_traits the default traits could be generated e.g. by specializing sqlpp::make_traits<>. Since it's impossible to define a default argument of a template parameters pack (another missing language feature?) it could be "simulated" with something like:

template