nextup(3) Library Functions Manual nextup(3) nextup, nextupf, nextupl, nextdown, nextdownf, nextdownl - / (libm -lm) #define _GNU_SOURCE /* feature_test_macros(7) */ #include double nextup(double x); float nextupf(float x); long double nextupl(long double x); double nextdown(double x); float nextdownf(float x); long double nextdownl(long double x); nextup() nextupf() nextupl() x. x -0. x +0 -0 . x . x . x NaN NaN. nextdown(x) -nextup(-x) . . attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |nextup(), | | MT-Safe | |nextupf(), | | | |nextupl(), | | | |nextdown(), | | | |nextdownf(),| | | |nextdownl() | | | +------------+------------------------------------+--------------------+ IEEE Std 754-2008 - ISO/IEC TS 18661. glibc 2.24. nearbyint(3), nextafter(3) 3 . . : . 6.18 8 2026 nextup(3)