How to disallow temporaries

Question

For a class Foo, is there a way to disallow constructing it without giving it a name?

For example:

Foo(\"hi\");

And only allow it i

Answer 1

Simply don't have a default constructor, and do require a reference to an instance in every constructor.

#include 
using namespace std;

enum SelfRef { selfRef };

struct S
{
    S( SelfRef, S const & ) {}
};

int main()
{
    S a( selfRef, a );
}