Question

$12.8/2 – ‘A non-template constructor
for class X is a copy constructor if
its first parameter is of type X&,
const X&, volatile X& or const
volatile X&, and either there are no
other parameters or else all other
parameters have default arguments
(8.3.6).106)’

So far, I have not come across any example of a situation where there is a need to declare a copy constructor with additional default parameters.

Would like to know any real time use of such a copy constructor which take more than one parameter.

Answer 1

The old std::basic_string does have one too:

basic_string(const basic_string& s, 
         size_type pos = 0, size_type n = npos)