On 09/27/2005 05:05 PM, Calum Grant wrote:
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[mailto:boost-bounces@lists.boost.org] On Behalf Of Larry Evans
Is there any interest in providing relational containers in Boost? Are there any features/improvements you can suggest for RML?
http://visula.org/relational/implementation.html contains:
The reason this has to be a macro is because it needs to work with names, not just types. It was felt that the benefits of being able to write customer.name or customers.name instead of column<1>(customers) or col<1,1>() outweighs the inherent disadvantages of using a macro.
why not use an enumerator:
column<name>(customers)
instead of a number:
column<1>(customers)
? Would this eliminate the macro need?
An early RML did use tuples indexed in the way you describe. I did use enums - writing magic numbers is very bad for readibility and
^^^^^^^^^^^^^ I guess you mean an enumeration here?
maintainability. Personally I prefer to read
customers.name
instead of
column<name>(customers)
Well, how about: customers.get<name>() IMO, that's only marginally more verbose and just as readable.
There is also a big problem with enums - being able to associate the correct enum with the correct type. I.e. the "name" column may be 2 for customers, and 3 for products. So you really need column<customer_name>(customers) and column<product_name>(product).
Or, customers.get<customers::name>() OK, that's a little less readable :( , but I guess you believe the disadvantage of macro use is not as bad as the disadvantage of prefixing customers:: to the enumerator. I'm not that sure.