SP>>class MyObject {
SP>>    int _v;
SP>>    public: MyObject setField(int v)&& { this->_v = v; return *this; }
SP>>}
SP>>

#include <string>
#include <cstdio>

using namespace std;

class MyObject {
    int _v;
    public: MyObject setField(int v)&& { this->_v = v; return *this; }
};

int main() {
    auto m = MyObject().setField(1); // ok

    auto m2 = MyObject();
    m2.setField(1); //  error: 'this' argument to member function 'setField' is an lvalue, but function has rvalue ref-qualifier
}