The size_in_bits function seems to take any type of parameter. This can be done by overloading the function, or by letting the compiler take care of it by writing a template. Which choice is an implementation of that template?

int main()
{
tout « size_in_bits(21) « endl;
tout « size_in_bits('f') « endl;
tout « size_in_bits(32.1f) « endl;
tout « size_in_bits(32.1) « endl;
return 0;
}