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From: Max Motovilov (max_at_[hidden])
Date: 2004-02-15 21:43:51

I may have posted something to this effect in Apr. 2003 but got no
response if I have; just thought I might have better luck the second time as
were no changes to the tuple library since then.

Proposal: current boost/tuple library has a hardcoded limit on the tuple
arity (10 elements). Some applications may require substantially larger
tuples even at a cost of extended compilation time. Using boost/preprocessor
library, it is relatively easy to rewrite the tuple code in such a way that
arity limit will depend on a single configuration macro without incuring any
other changes to the library. No additional cost will be imposed on the
users who are satisifed with the current tuple library.

I have a working implementation of such configurable tuples that I've been
using since Apr. 2003. As I had no need to support C++ compilers that do not
implement partial specification, I have only converted
boost/tuple/detail/tuple_basic.hpp so far. Arity limit is controlled by the
BOOST_TUPLE_MAX_ARITY macro which is defaulted to 10 inside tuple_basic.hpp
if it is not defined prior to its inclusion. Since I am not sure what
procedure should I follow to submit such a modification to an existing Boost
library, I decided just to post the proposal here and provide a link to the
modifed file:


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