golden hour

/usr/include/bits

File/Folder	Size	Actions
a.out.h	268 B
byteswap-16.h	1.69 KB
byteswap.h	5.56 KB
cmathcalls.h	4.7 KB
confname.h	23.19 KB
dirent.h	1.69 KB
dlfcn.h	2.47 KB
elfclass.h	426 B
endian.h	176 B
environments.h	3.5 KB
epoll.h	1.11 KB
errno.h	2.11 KB
error.h	2.62 KB
eventfd.h	1.1 KB
fcntl-linux.h	12.55 KB
fcntl.h	2.19 KB
fcntl2.h	5.44 KB
fenv.h	3.94 KB
fenvinline.h	190 B
huge_val.h	1.83 KB
huge_valf.h	1.79 KB
huge_vall.h	1.57 KB
hwcap.h	966 B
in.h	9.01 KB
inf.h	1.03 KB
initspin.h	25 B
inotify.h	1.05 KB
ioctl-types.h	2.41 KB
ioctls.h	4.38 KB
ipc.h	2.01 KB
ipctypes.h	1.14 KB
libc-lock.h	12.54 KB
libio-ldbl.h	1014 B
link.h	4.2 KB
local_lim.h	3.13 KB
locale.h	1.33 KB
math-finite.h	14.24 KB
mathcalls.h	11.3 KB
mathdef.h	2.14 KB
mathinline.h	30.86 KB
mman.h	4.78 KB
monetary-ldbl.h	1.02 KB
mqueue.h	1.22 KB
mqueue2.h	2.11 KB
msq.h	2.47 KB
nan.h	1.54 KB
netdb.h	1.25 KB
param.h	1.4 KB
poll.h	2.04 KB
poll2.h	2.86 KB
posix1_lim.h	4.81 KB
posix2_lim.h	2.82 KB
posix_opt.h	5.65 KB
printf-ldbl.h	986 B
pthreadtypes.h	6.33 KB
resource.h	9.21 KB
sched.h	7.37 KB
select.h	2.08 KB
select2.h	1.4 KB
sem.h	2.53 KB
semaphore.h	1.21 KB
setjmp.h	1.26 KB
setjmp2.h	1.67 KB
shm.h	3.44 KB
sigaction.h	2.79 KB
sigcontext.h	4.08 KB
siginfo.h	9.81 KB
signalfd.h	1.04 KB
signum.h	3.34 KB
sigset.h	4.48 KB
sigstack.h	1.49 KB
sigthread.h	1.64 KB
sockaddr.h	1.5 KB
socket.h	12.6 KB
socket2.h	2.95 KB
socket_type.h	2.16 KB
stab.def	8.82 KB
stat.h	7.46 KB
statfs.h	1.89 KB
statvfs.h	3.34 KB
stdio-ldbl.h	3.11 KB
stdio-lock.h	2.14 KB
stdio.h	5.45 KB
stdio2.h	12.36 KB
stdio_lim.h	1.34 KB
stdlib-float.h	1.12 KB
stdlib-ldbl.h	1.36 KB
stdlib.h	5.53 KB
string.h	56.48 KB
string2.h	46.08 KB
string3.h	4.38 KB
sys_errlist.h	1.19 KB
syscall.h	43.03 KB
sysctl.h	893 B
syslog-ldbl.h	1.17 KB
syslog-path.h	1.03 KB
syslog.h	1.66 KB
termios.h	5.23 KB
time.h	3.35 KB
timerfd.h	1.08 KB
timex.h	4.36 KB
types.h	7.55 KB
typesizes.h	3.15 KB
uio.h	2.42 KB
unistd.h	13.07 KB
ustat.h	1.06 KB
utmp.h	3.87 KB
utmpx.h	3.38 KB
utsname.h	1.19 KB
waitflags.h	1.61 KB
waitstatus.h	3.49 KB
wchar-ldbl.h	2.45 KB
wchar.h	1.11 KB
wchar2.h	20.04 KB
wordsize.h	327 B
xopen_lim.h	3.68 KB

Edit: cmathcalls.h

/* Prototype declarations for complex math functions;
   helper file for <complex.h>.
   Copyright (C) 1997, 1998, 2001, 2007 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/* NOTE: Because of the special way this file is used by <complex.h>, this
   file must NOT be protected from multiple inclusion as header files
   usually are.

This file provides prototype declarations for the math functions.
   Most functions are declared using the macro:

__MATHCALL (NAME, (ARGS...));

This means there is a function `NAME' returning `double' and a function
   `NAMEf' returning `float'.  Each place `_Mdouble_' appears in the
   prototype, that is actually `double' in the prototype for `NAME' and
   `float' in the prototype for `NAMEf'.  Reentrant variant functions are
   called `NAME_r' and `NAMEf_r'.

Functions returning other types like `int' are declared using the macro:

__MATHDECL (TYPE, NAME, (ARGS...));

This is just like __MATHCALL but for a function returning `TYPE'
   instead of `_Mdouble_'.  In all of these cases, there is still
   both a `NAME' and a `NAMEf' that takes `float' arguments.  */

#ifndef _COMPLEX_H
#error "Never use <bits/cmathcalls.h> directly; include <complex.h> instead."
#endif

#define _Mdouble_complex_ _Mdouble_ _Complex

/* Trigonometric functions.  */

/* Arc cosine of Z.  */
__MATHCALL (cacos, (_Mdouble_complex_ __z));
/* Arc sine of Z.  */
__MATHCALL (casin, (_Mdouble_complex_ __z));
/* Arc tangent of Z.  */
__MATHCALL (catan, (_Mdouble_complex_ __z));

/* Cosine of Z.  */
__MATHCALL (ccos, (_Mdouble_complex_ __z));
/* Sine of Z.  */
__MATHCALL (csin, (_Mdouble_complex_ __z));
/* Tangent of Z.  */
__MATHCALL (ctan, (_Mdouble_complex_ __z));

/* Hyperbolic functions.  */

/* Hyperbolic arc cosine of Z.  */
__MATHCALL (cacosh, (_Mdouble_complex_ __z));
/* Hyperbolic arc sine of Z.  */
__MATHCALL (casinh, (_Mdouble_complex_ __z));
/* Hyperbolic arc tangent of Z.  */
__MATHCALL (catanh, (_Mdouble_complex_ __z));

/* Hyperbolic cosine of Z.  */
__MATHCALL (ccosh, (_Mdouble_complex_ __z));
/* Hyperbolic sine of Z.  */
__MATHCALL (csinh, (_Mdouble_complex_ __z));
/* Hyperbolic tangent of Z.  */
__MATHCALL (ctanh, (_Mdouble_complex_ __z));

/* Exponential and logarithmic functions.  */

/* Exponential function of Z.  */
__MATHCALL (cexp, (_Mdouble_complex_ __z));

/* Natural logarithm of Z.  */
__MATHCALL (clog, (_Mdouble_complex_ __z));

#ifdef __USE_GNU
/* The base 10 logarithm is not defined by the standard but to implement
   the standard C++ library it is handy.  */
__MATHCALL (clog10, (_Mdouble_complex_ __z));
#endif

/* Power functions.  */

/* Return X to the Y power.  */
__MATHCALL (cpow, (_Mdouble_complex_ __x, _Mdouble_complex_ __y));

/* Return the square root of Z.  */
__MATHCALL (csqrt, (_Mdouble_complex_ __z));

/* Absolute value, conjugates, and projection.  */

/* Absolute value of Z.  */
__MATHDECL (_Mdouble_,cabs, (_Mdouble_complex_ __z));

/* Argument value of Z.  */
__MATHDECL (_Mdouble_,carg, (_Mdouble_complex_ __z));

/* Complex conjugate of Z.  */
__MATHCALL (conj, (_Mdouble_complex_ __z));

/* Projection of Z onto the Riemann sphere.  */
__MATHCALL (cproj, (_Mdouble_complex_ __z));

/* Decomposing complex values.  */

/* Imaginary part of Z.  */
__MATHDECL (_Mdouble_,cimag, (_Mdouble_complex_ __z));

/* Real part of Z.  */
__MATHDECL (_Mdouble_,creal, (_Mdouble_complex_ __z));

/* Now some optimized versions.  GCC has handy notations for these
   functions.  Recent GCC handles these as builtin functions so does
   not need inlines.  */
#if defined __GNUC__ && !__GNUC_PREREQ (2, 97) && defined __OPTIMIZE__ \
    && defined __extern_inline

/* Imaginary part of Z.  */
__extern_inline _Mdouble_
__MATH_PRECNAME(cimag) (_Mdouble_complex_ __z) __THROW
{
  return __imag__ __z;
}

/* Real part of Z.  */
__extern_inline _Mdouble_
__MATH_PRECNAME(creal) (_Mdouble_complex_ __z) __THROW
{
  return __real__ __z;
}

/* Complex conjugate of Z.  */
__extern_inline _Mdouble_complex_
__MATH_PRECNAME(conj) (_Mdouble_complex_ __z) __THROW
{
  return __extension__ ~__z;
}

#endif