cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration wchar/open_wmemstream.c -o wchar/open_wmemstream -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
wchar/open_wmemstream.c: In function ‘main’:
wchar/open_wmemstream.c:11:20: error: implicit declaration of function ‘open_wmemstream’; did you mean ‘open_memstream’? [-Wimplicit-function-declaration]
   11 |         FILE* fp = open_wmemstream(&buf, &size);
      |                    ^~~~~~~~~~~~~~~
      |                    open_memstream
wchar/open_wmemstream.c:11:20: error: initialization of ‘FILE *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
wchar/open_wmemstream.c:20:14: error: implicit declaration of function ‘fwprintf’; did you mean ‘fprintf’? [-Wimplicit-function-declaration]
   20 |         if ( fwprintf(fp, L"hello %ls %d", L"world", 42) < 0 )
      |              ^~~~~~~~
      |              fprintf