std::set iterator automatically const [duplicate]

Answer 1

I you are certain you won't touch the variables that are used for the sorting the you could work around this by using a const_cast like this:

    MyClass tmpClass;
    std::set<MyClass > setMyClass;
    setMyClass.insert(tmpClass);
    std::set<MyClass >::iterator iter;
    iter=setMyClass.begin();
    const MyClass &tmpClass2=*iter;

    MyClass &tmpClass3 = const_cast<MyClass&>(tmpClass2);

Alternatively, you could declare the members of the class that you intend to change as mutable.

Answer 2

Yes, this is expected. If you were able to edit the objects already in the set, the applied sort order might no longer apply, leading to undefined behaviour.