摘要： int val(){ int i = 1; return i;}int & ref(){ int i = 1; return i;}int main(){ int vv = val(); int & rv = val(); int vr = ref(); int & rr = ref();}区别和问题：int vv = val(); // int <= int;没有问题，值传递int & rv = val(); // int& <= int;或int& <= const int&;编译错误int vr = ref(); 阅读全文