Hi List,
I cannot find anywhere in the standard if the following is legal or not:

class outer
{
public:
  class inner;
};

class other_class
{
  class outer::inner
  {
  public:
    int i;
  };

  // ...

};

int main()
{
  outer::inner a;
  a.i = 2;
  return 0;
}

I.e. can be a class defined outside of its "real" container scope
(namely in an another namespace- or class-scope)?

(Btw my compiler -- MSVC6 -- compiles the above code).


Thanks,
  Arpad.

--
***********************************************
*  Arpad Beszedes (research engineer)         *
*                                             *
*  Research Group on Artificial Intelligence  *
*  Hungarian Academy of Sciences              *
*  Attila Jozsef University, Szeged, Hungary  *
*  e-mail: beszedes@cc.u-szeged.hu            *
*  tel.: (+36) 62/544-145                     *
***********************************************
* "To err is human, but to really mess things *
*          up you need a computer."           *
***********************************************

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In article <38FD77E7.F3F90217@cc.u-szeged.hu> Beszedes Arpad <beszedes@cc.u-szeged.hu> writes:
>I cannot find anywhere in the standard if the following is legal or not:
>class outer
>{
>public:
>  class inner;
>};
>
>class other_class
>{
>  class outer::inner
>  {
>  public:
>    int i;
>  };
>  // ...
>};
>....
>I.e. can be a class defined outside of its "real" container scope
>(namely in an another namespace- or class-scope)?

Namespace yes, its class yes, other class no.

>(Btw my compiler -- MSVC6 -- compiles the above code).

Comeau C++ gives:
line 9: error: class "outer::inner" cannot be defined in the current scope
    class outer::inner
          ^

which is backed up by 9.7p3: "If class X is defined in a namespace scope,
a nested class Y may be declared in class X and later defined in the
definition of class X or be later defined in a namespace scope enclosing
the definition of class X." Since other_class is not a namespace
scope or within outer, then defining outer::inner in other_class
is an error.

- Greg
--
Comeau Computing, Producers of Comeau C/C++ 4.2.42 (4.2.43 BETA starting)
Try Comeau C++ online at http://www.comeaucomputing.com/tryitout
Email: comeau@comeaucomputing.com / WEB: http://www.comeaucomputing.com

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