INFINITY(3) Library Functions Manual INFINITY(3) INFINITY, NAN, HUGE_VAL, HUGE_VALF, HUGE_VALL - LIBRARY Math library (libm) #define _ISOC99_SOURCE /* feature_test_macros(7) */ #include INFINITY NAN HUGE_VAL HUGE_VALF HUGE_VALL INFINITY float, . NAN float, (quiet) NaN ( ). NaN -- NaN (<< >>), . -- (signaling) NaN. IEC 60559:1989. The macros HUGE_VAL, HUGE_VALF, HUGE_VALL expand to constants of types double, float, and long double, respectively, that represent a large positive value, possibly positive infinity. C11. C99. glibc HUGE_VAL . NAN #ifdef NAN; INFINITY, HUGE_VALF, HUGE_VALL. , _ISOC99_SOURCE, _GNU_SOURCE __STDC_VERSION__ 199901L. . fpclassify(3), math_error(7) Azamat Hackimov , Dmitriy S. Seregin , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . INFINITY(3)