.\" Modified 2002-07-27 by Walter Harms
.\" (walter.harms@informatik.uni-oldenburg.de)
.\"
-.TH EXP 3 2015-04-19 "" "Linux Programmer's Manual"
+.TH EXP 3 2017-09-15 "" "Linux Programmer's Manual"
.SH NAME
exp, expf, expl \- base-e exponential function
.SH SYNOPSIS
.nf
.B #include <math.h>
-.sp
+.PP
.BI "double exp(double " x );
-.br
.BI "float expf(float " x );
-.br
.BI "long double expl(long double " x );
.fi
-.sp
+.PP
Link with \fI\-lm\fP.
-.sp
+.PP
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
-.sp
+.PP
.ad l
.BR expf (),
.BR expl ():
.RS 4
-_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
-_POSIX_C_SOURCE\ >=\ 200112L;
-.br
-or
-.I cc\ -std=c99
+_ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
+ || /* Since glibc 2.19: */ _DEFAULT_SOURCE
+ || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.ad b
.SH DESCRIPTION
.SH RETURN VALUE
On success, these functions return the exponential value of
.IR x .
-
+.PP
If
.I x
is a NaN,
a NaN is returned.
-
+.PP
If
.I x
is positive infinity,
positive infinity is returned.
-
+.PP
If
.I x
is negative infinity,
+0 is returned.
-
+.PP
If the result underflows,
a range error occurs,
and zero is returned.
-
+.PP
If the result overflows,
a range error occurs,
and the functions return
.BR math_error (7)
for information on how to determine whether an error has occurred
when calling these functions.
-
+.PP
The following errors can occur:
.TP
Range error, overflow
.TE
.SH CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
-
+.PP
The variant returning
.I double
also conforms to