copysign(3) Library Functions Manual copysign(3) copysign, copysignf, copysignl - (libm, -lm) #include double copysign(double x, double y); float copysignf(float x, float y); long double copysignl(long double x, long double y); glibc (. feature_test_macros(7)): copysign(), copysignf(), copysignl(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE , x, y. , copysign(42.0, -1.0) copysign(-42.0, -1.0) -42.0. x y. x NaN, NaN y. . attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |copysign(), copysignf(), | | MT-Safe | |copysignl() | | | +----------------------------+----------------------------------------------------------+--------------------------+ , IEEE 754, . C11, POSIX.1-2008. IEC 559 ( IEEE 754/IEEE 854). C99, POSIX.1-2001, 4.3BSD. signbit(3) () Azamat Hackimov , Dmitriy S. Seregin , Dmitry Bolkhovskikh , Katrin Kutepova , Yuri Kozlov , Kirill Rekhov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. Linux 6.9.1 2 2024 . copysign(3)