Compile error #1

Compilation error:

alex@genty:/tmp/hid_mapper$ make
g++ -c -Iinclude -fPIC main.cpp
gcc -c -g -O2 -Iinclude -fPIC uinput_device.c
gcc -c -g -O2 -Iinclude -fPIC hid.c
In file included from hid.c:21:0:
include/log.h:36:6: warning: conflicting types for built-in function 'log'
void log(LogLevel severity, const char* fmt, va_list args);
^
hid.c: In function 'read_hid_event':
hid.c:232:2: error: unknown type name 'fd_set'
fd_set rfds;
^
Makefile:48: recipe for target 'hid.o' failed
make: *** [hid.o] Error 1

Adding #include <sys/select.h> in hid.c seems to fix it.