-fpack-struct doesn't work under g++

[Tom]

The switch '-fpack-struct' doesn't pack structs under g++.


g++ --version
egcs-2.90.29 980515 (egcs-1.0.3 release)


typdef struct
{
	unsigned short a;
	unsigned long b;
} MyStruct;

void main(int argc, char** argv)
{
	MyStruct S;
	printf("%d\n",(unsigned long)&S.b - (unsigned long)&S);
}


g++ -fpack-struct -c test.cpp -o test.o
g++ test.o -o test

The result when run is:
4

when it should be:
2

Tom