cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations stdio/vscanf.c -o stdio/vscanf -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
stdio/vscanf.c:5:34: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Werror,-Wimplicit-int]
int (*foo)(const char *restrict, va_list) = vscanf;
                                 ^
                                 int
stdio/vscanf.c:5:7: error: incompatible function pointer types initializing 'int (*)(const char *restrict, int)' with an expression of type 'int (const char *restrict, struct __va_list_tag *)' [-Werror,-Wincompatible-function-pointer-types]
int (*foo)(const char *restrict, va_list) = vscanf;
      ^                                     ~~~~~~
2 errors generated.