I want to know the meaning of & in the example below:
class1 &class1::instance(){
///something to do
}
The & operator has three meanings in C++.
2 & 1 == 3int x = 3; int* ptr = &x;int x = 3; int& ref = x;Here you have a reference type modifier. Your function class1 &class1::instance() is a member function of type class1 called instance, that returns a reference-to-class1. You can see this more clearly if you write class1& class1::instance() (which is equivalent to your compiler).