signbit

Test for sign bit. The scalar version of the function returns a 1 if the sign bit in the float is set else returns 0.

template <typename F, typename return_t, detail::enable_if_t<(detail::builtin::is_genfloat<F>::value), int> >
return_t signbit(F x)

1. Test for sign bit. The scalar version of the function returns a 1 if the sign bit in the float is set else returns 0.
   Parameters:
   • F x