exp2 (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
and Copyright 2008, Linux Foundation, written by Michael Kerrisk
<mtk.manpages@gmail.com>
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NAME
exp2, exp2f, exp2l - base-2 exponential functionSYNOPSIS
#include <math.h> double exp2(double x);
float exp2f(float x);
long double exp2l(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
exp2(), exp2f(), exp2l():
-
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
These functions return the value of 2 raised to the power of x.RETURN VALUE
On success, these functions return the base-2 exponential value of x.For various special cases, including the handling of infinity and NaN, as well as overflows and underflows, see exp(3).
ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.For a discussion of the errors that can occur for these functions, see exp(3).
VERSIONS
These functions first appeared in glibc in version 2.1.ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
| exp2(), exp2f(), exp2l() | Thread safety | MT-Safe |
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.The variant returning double also conforms to SVr4, 4.3BSD, C89.