Gennaro Prota wrote:
TR1 asks for a non-macro version:
template<class T> bool signbit(T x);
Like its C99 counterpart (which formally yields an int, but the behavior is bool-like: nonzero iff the argument value has negative sign) it shall work for any floating point value, including, if supported, signed zeros, infinities and NaNs. I didn't try but I guess the only slightly tricky point to watch for is signaling NaNs.
And the endianness of the float's if you're doing bit testing. But of course if there is a macro already it's easy enough to convert it into a function.
Note that all this is quite different, in scope and semantics, from your sign facility, which BTW could perhaps be "extended" to:
template <class T> int sign(const T& v) { return v < 0 ? -1 : (v > 0 ? 1 : 0) }
I know, but I'm not sure about it :-) Or at least it complicates the uses I had for it, maybe I'll demote it to a detail... John.