clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations netinet_in/ntohs.c -o netinet_in/ntohs -D_POSIX_C_SOURCE=202405L  -lm  -lintl
netinet_in/ntohs.c:3:12: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
uint16_t (*foo)(uint16_t) = ntohs;
           ^
netinet_in/ntohs.c:3:1: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
uint16_t (*foo)(uint16_t) = ntohs;
^
netinet_in/ntohs.c:3:17: error: a parameter list without types is only allowed in a function definition
uint16_t (*foo)(uint16_t) = ntohs;
                ^
netinet_in/ntohs.c:3:10: error: function cannot return function type 'int ()'
uint16_t (*foo)(uint16_t) = ntohs;
         ^
netinet_in/ntohs.c:3:29: error: use of undeclared identifier 'ntohs'
uint16_t (*foo)(uint16_t) = ntohs;
                            ^
5 errors generated.