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.