Talk:cpp/language/nested types


[edit] C++11 changes?

I'm pretty sure that C++11 changed the rules for nested classes slightly. Specifically, I recall that nested classes are now considered a first-class member of their outer class, so they can access private and protected data members of their enclosing class and can be declared/defined in any order. Can this be confirmed and updated? LB(T|C) 13:01, 28 March 2014 (PDT)

Yes, I missed the small change in 9.5/1 from 03 to 11. Updated (changes weren't that drastic though, you could always access private members) --Cubbi (talk) 14:17, 28 March 2014 (PDT)

[edit] As there are two Xes.

As of 20 Apr 2014 there is such a code snippet on the page:

int x,y; // globals
class enclose { // enclosing class
    int x; // note: private members
    static int s;
    struct inner { // nested class
        void f(int i) {
            x = i; // Error: can't write to non-static enclose::x without instance
            int a = sizeof x; // Error until C++11,
                              // OK in C++11: operand of sizeof is unevaluated, this use is ok

It raise a question about the value of a:

  • In the statement a get size of a private member or of the global x?

Would it be better to make global x and private x of different types and add the actual value of a in the comments, wouldn't it?

I added a comment to say which x is found by lookup at that line, although it isn't different from one line above. --Cubbi (talk) 12:55, 20 April 2014 (PDT)

[edit] Is the current title appropriate?

It seems that nested class is better than nested types, as nested types can also be nested typedef's, but this page doesn't talk anything about that. -- 08:17, 17 May 2014 (PDT)

True, this isn't about nested typedef declarations (which are mentioned briefly in a few places, but not here). Changed title. --Cubbi (talk) 12:05, 21 May 2014 (PDT)