ceil, ceilf, ceill - ceiling function: smallest integral
value not less than argument
SYNOPSIS
#include <math.h>
double ceil(double x);
float ceilf(float x);
long double ceill(long double x);
DESCRIPTION
These functions round x up to the nearest integer.
RETURN VALUE
The rounded integer value. If x is integral or infinite, x
itself is returned.
ERRORS
No errors other than EDOM and ERANGE can occur. If x is
NaN, then NaN is returned and errno may be set to EDOM.
NOTES
The SUSv2 and Austin draft contain text about overflow
(which might set errno to ERANGE, or raise an exception).
In practice, the result cannot overflow on any current
machine, so this error-handling stuff is just nonsense.
(More precisely, overflow can happen only when the maximum
value of the exponent is smaller than the number of man
tissa bits. For the IEEE-754 standard 32-bit and 64-bit
floating point numbers the maximum value of the exponent
is 128 (resp. 1024), and the number of mantissa bits is 24
(resp. 53).)
CONFORMING TO
The ceil() function conforms to SVID 3, POSIX, BSD 4.3,
ISO 9899. The other functions are from C99.
SEE ALSO
floor(3), lrint(3), nearbyint(3), rint(3), round(3),
trunc(3)
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