Sunday, March 06, 2005
Write Code to identify C or C++
#includechar xxx;
int main(){
struct xxx {
char c1;
int i;
char c2;
};
printf("in %s the size of xxx is %d\n",
sizeof(xxx)==1?"C":"C++",
sizeof(xxx));
}
rommel:~/puzzle> g++ -o m.o -c C_Cpp.c
rommel:~/puzzle> g++ -o m m.o
rommel:~/puzzle> ./m
in C++ the size of xxx is 12
rommel:~/puzzle> cc -o m1.o -c C_Cpp.c
rommel:~/puzzle> cc -o m1 m1.o
rommel:~/puzzle> ./m1
in C the size of xxx is 1
Another thing we should notice is the size of struct xxx is 12 not 8(2+4+2)! This is because the integers are laid out on four-byte boudaries.
If we change the defintion to
struct xxx {
char c1;
char c2;
int i;
}
the size of struct xxx will be 8!.
- posted by Pop @ 10:10 PM
