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From: David Abrahams (dave_at_[hidden])
Date: 2005-10-23 09:07:50

"Andy Little" <andy_at_[hidden]> writes:

> "David Abrahams" wrote
>> "Andy Little" writes:
>>> I am arguing for a normalised version, so for my_rational<2,8>,
>>> my_rational<3,12> and my_rational<5,20> among others, the normalised
>>> version
>>> is my_rational<1,4> and thats what I think rational<...>::type should return.
>> Why should that normalization be done eagerly? I can see no good
>> reason for it.
> Numerator and denominator members are evaluated already . I guess you could
> remove them....

I don't see what the presence of numerator and denominator has to do
with normalization.

> [cut]
>> Is it daft to want my_rational<x,1> to be a conforming MPL integral
>> constant?
> Who wants special cases?

Who suggested a special case?

> integral constant can be converted to a
> rational constant, but not necessarily the other way.

Don't forget that the types are all known at compile-time. The usual
runtime logic doesn't necessarily apply. A conversion from
my_rational<x,1> to int_<x> is not a narrowing conversion.

Dave Abrahams
Boost Consulting

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