27 Feb
2008
27 Feb
'08
3:40 p.m.
Quoting Johan Råde <rade@maths.lth.se>:
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.
What should this function return for a NaN?
A NaN?