cc -pthread   -Wall -Wextra -Werror=implicit-function-declaration math/modfl.c -o math/modfl -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt  -lintl -liconv
math/modfl.c:10: warning: ignoring ‘#pragma STDC FENV_ACCESS’ [-Wunknown-pragmas]
   10 | #pragma STDC FENV_ACCESS ON
math/modfl.c: In function ‘test’:
math/modfl.c:38:30: error: implicit declaration of function ‘modfl’ [-Wimplicit-function-declaration]
   38 |         long double output = modfl(input1, &integral);
      |                              ^~~~~
math/modfl.c:9:1: note: include ‘<math.h>’ or provide a declaration of ‘modfl’
    8 | #include "../basic.h"
  +++ |+#include <math.h>
    9 | 
math/modfl.c:38:30: warning: incompatible implicit declaration of built-in function ‘modfl’ [-Wbuiltin-declaration-mismatch]
   38 |         long double output = modfl(input1, &integral);
      |                              ^~~~~
math/modfl.c:38:30: note: include ‘<math.h>’ or provide a declaration of ‘modfl’