[boost] [GSoC] [Checks] Issue with the design

Subject: [boost] [GSoC] [Checks] Issue with the design
From: Pierre Talbot (pierre.talbot.6114_at_[hidden])
Date: 2011-08-01 15:15:20

Hello everyone.

We talked a few days ago about the design of the check library (about
the compile or run-time weight parameter.)
Reminder : the weights are the contribution to the running sum of a
digit in a number.

I used and followed your ideas and suggestions that bring me to the
policies class.

I tried to extract the characteristics of a "generic" check and the
weight is one of these. So I tried to implement the weight policy
class :

#define _WEIGHT_factory(z,n,unused) \
  template<BOOST_PP_ENUM_PARAMS(n, int weight)> \
  struct weight_policy \
  { typedef typename boost::mpl::vector_c<int BOOST_PP_COMMA_IF(n)
BOOST_PP_ENUM_PARAMS(n, weight)> weight ; } ; \

BOOST_PP_REPEAT_FROM_TO(1,BOOST_CHECK_LIMIT_WEIGHTS,_WEIGHT_factory,~)

#undef _WEIGHT_factory

But the compiler doesn't like the "struct template parameter
overloading". Is a limit of the language ? Or am I doing it in the
wrong way ?
If it's impossible, I though that we could passed the weights to a
function that aimed to "build" the vector_c type.

While we speak about the design, what do you think about the policies
class ? There are useful because the core of the algorithm is the same
for every checks.

Every critics or suggestions are welcomed,

thank you,

Pierre Talbot.