7.12.3.6 The signbit macro

Synopsis

1

#include <math.h>
int signbit(real-floating x);

Description

2

The signbit macro determines whether the sign of its argument value is negative.[1]

Returns

3

The signbit macro returns a nonzero value if and only if the sign of its argument value is negative.

Footnotes

[1]

The signbit macro reports the sign of all values, including infinities, zeros, and NaNs. If zero is unsigned, it is treated as positive.