I’m looking for a simple example when C++ 23 auto(x) could be useful.

This is what I have so far:

struct  A {
    A() = default;
    explicit A(const A&) {} // copy constructor
};
struct B {
    A child;
};

template<class T>
void printChild(T t) {
}

template<class T>
void printParent(T t) {
    // printChild(t.child); // Error - copy ctr is explicit
    printChild(A(t.child)); // if we knew the type
    printChild(auto(t.child)); // in C++23
}


   
int main() {
    B b;
    printParent(b);
}

Now I’m looking for a simple example without an explicit constructor, and perhaps another one where the decay_copy benefit is shown. The examples I’ve found online so far have not been clear to me.