c++ passing arguments by reference and pointer

Question

in c++

class bar
{
    int i;
    char b;
    float d;
};

void foo ( bar arg );
void foo ( bar &arg );
void foo ( bar *arg );

this i

Answer 1

If you consider that it's good practice to validate pointer parameters before using them then, yes, pointers introduce extra overhead since references don't require such testing.