sum of two integers

[Jerry Coffin]

[ ... ]

(I might add that I can't think of
a more inefficient way of adding two numbers.)

I'm sure you could if you tried.

int add(int i, int j) {
std:fstream x("somename", std::ios::binary);

std::string a(i, ' ');
std::string b(j, ' ');

x << a;
x << b;

x.seekp(i, std::ios::begin);
x.seekp(j, std::ios::cur);

return x.tellp();
}

Much like your string-based solution, there's little room for question
that this is just hiding the arithmetic, not really avoiding it. The
gyrations with seekp even add a bit of flexibility: this works when j is
negative, as long as its magnitude is smaller than i's.