cc -pthread   -Wall -Wextra -Werror=implicit-function-declaration complex/cexpl.c -o complex/cexpl -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt  -lintl -liconv
complex/cexpl.c:11: warning: ignoring ‘#pragma STDC FENV_ACCESS’ [-Wunknown-pragmas]
   11 | #pragma STDC FENV_ACCESS ON
complex/cexpl.c: In function ‘test’:
complex/cexpl.c:24:38: error: implicit declaration of function ‘cexpl’ [-Wimplicit-function-declaration]
   24 |         long double complex output = cexpl(input1);
      |                                      ^~~~~
complex/cexpl.c:10:1: note: include ‘<complex.h>’ or provide a declaration of ‘cexpl’
    9 | #include "../basic.h"
  +++ |+#include <complex.h>
   10 | 
complex/cexpl.c:24:38: warning: incompatible implicit declaration of built-in function ‘cexpl’ [-Wbuiltin-declaration-mismatch]
   24 |         long double complex output = cexpl(input1);
      |                                      ^~~~~
complex/cexpl.c:24:38: note: include ‘<complex.h>’ or provide a declaration of ‘cexpl’