n3290 : Elaborated type specifiers syntax changed?

point From 2003 C++03 Document :

Elaborated type specifiers :section 3.4.4, para 1:

     "An elaborated-type-specifier  may be used to refer to  a
      previously declared class-name or enum-name even  though
      the name has been hidden by a non-type declaration.  **The
      class-name or enum-name in the elaborated-type-specifier
      may either be a simple identifier or be a qualified-id.**"

But in n3290 Draft they changed the Elaborated type specifiers (7.1.6.3)

7.1.6.3: Elaborated type specifiers

 elaborated-type-specifier:
     class-key attribute-specifier-seqopt nested-name-specifieropt identifier
     class-key nested-name-specifieropt templateopt simple-template-id
     enum nested-name-specifieropt identifier

May i know

1) what is the problem with earlier Syntax which supports typename c++03

     7.1.5.3 Elaborated type specifiers

 elaborated-type-specifier:
      class-key ::opt nested-name-specifieropt identifier
      class-key ::opt nested-name-specifieropt templateopt template-id
      enum ::opt nested-name-specifieropt identifier
      typename ::opt nested-name-specifier identifier
      typename ::opt nested-name-specifier templateopt template-id

2) IS that really compiler is following/not folling this rule...(which compiler supports this change )

3) When开发者_开发技巧 coming to the above point 3.4.4/1st

      The class-name or enum-name in the elaborated-type-specifier
      may either be a simple identifier or be a qualified-id

why it is not allowed in c++0x.

Please any one explain this ? Please any one explain this ?

(When iam trying to add c++0x TAG it is not ..tagging ..please any one ..Add c++0x tag ? )

1. This is a simple reorganization. typename-specifier is now not a kind of elaborated-type-specifier, but they are both kinds of trailing-type-specifier.
2. It's not clear what the compilers should do. Can you think of valid C++03 code that is not a valid C++0x?
3. What exactly is not allowed in C++0x? The grammar says a qualified-id is allowed there, as nested-name-specifier_opt identifier.