Rounds to the nearest integer value in a floating-point format.
#include <math.h> double round (x) double x; float roundf (x) float x; long double roundl (x) long double x;
The round, roundf, and roundl subroutines round the x parameter to the nearest integer value in floating-point format, rounding halfway cases away from zero, regardless of the current rounding direction.
An application wishing to check for error situations should set the errno global variable to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these subroutines. Upon return, if errno is nonzero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is nonzero, an error has occurred.
| x | Specifies the value to be rounded. |
Upon successful completion, the round, roundf, and roundl subroutines return the rounded integer value.
If x is NaN, a NaN is returned.
If x is ±0 or ±Inf, x is returned.
If the correct value would cause overflow, a range error occurs and the round, roundf, and roundl subroutines return the value of the macro ±HUGE_VAL, ±HUGE_VALF, and ±HUGE_VALL (with the same sign as x), respectively.
feclearexcept Subroutine and fetestexcept Subroutine in AIX 5L Version 5.2 Technical Reference: Base Operating System and Extensions Volume 1.
math.h in AIX 5L Version 5.2 Files Reference.