You should post the actual code that you tried. In your first example, you should be getting a compile error, not a linker error, because the struct has no member named myMember.

Compile and link this program:
Code:
struct nameOfStruct
{
    int myMember1;
    short myMember2;
};

int main()
{
    nameOfStruct myInstance;
    myInstance.myMember1 = 444;
    return 0;
}