Re: [boost] Ann: Floating Point Utilities Review starts today

From: John Maddock (john_at_[hidden])
Date: 2008-02-27 11:33:41

Johan Råde wrote:
> John Maddock wrote:
>
>> There is one other useful function worth having IMO:
>>
>> template <class T>
>> int sign(T x);
>>
>> returns 0 (x is zero), +1 (x is > 0) or -1 (x is < 0).  This is
>> trivial to implement (lot's of old C code - for example the
>> Numerical Recipies stuff - implement this as a helper macro), and
>> there's an undocumented version currently in Boost.Math.  Is this
>> worth integrating with Johan's code?  I've found it quite useful in
>> Boost.Math from time to time.
>
> The library deals with signbits, not with signs.

Nod, understood.

> So I think that adding this function to the library would just create
> confusion. It may be a useful function, but I don't think it belongs
> here.

Maybe, maybe not.  I was just thinking to locate all the sign-related 
functions in one place rather than scatter them round the place, but it can 
always remain an implementation detail if it doesn't fit in well with the 
rest.

John.