Re: [boost] [fusion] Support for classic boost::tuple

From: David Abrahams (dave_at_[hidden])
Date: 2006-09-29 11:58:48

Joel de Guzman <joel_at_[hidden]> writes:

> Here's another problem:
>
>      std::map<int*, int*> m;
>
> generic code that treats pair<int* int*> as an iterator_range
> will treat m's data type incorrectly.

No, generic code doesn't look at types and say, "which of two concepts
with no refinement relationship does this type fulfill?" and then take
different actions based on the answer.  The only such type-based
dispatching in generic code comes through algorithm specialization:
"this type fulfills concept X, but also concept Y which is a
refinement of X, so I'll use that information to do whatever I was
going to do more efficiently."

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com