alias-declaration issue in 15.0

The following code does not compile:

using Type alignas(4) = int;

According to clause 7 of the standard I think it should:

7 (1):

alias-declaration: using identifier attribute-specifier-seq_opt = type-id ;

7.6.1 (1):

attribute-specifier-seq:

attribute-specifier-seq_opt attribute-specifier

attribute-specifier:

[ [ attribute-list ] ]

alignment-specifier

alignment-specifier:

alignas ( type-id ..._opt)

alignas ( alignment-expression ..._opt)

I use MSVC2013 and either the v120 or CTP_Nov2013 base platform toolset.

Both Microsoft compilers don't compile either. Is this the reason why yours doesn't compile (just like with no implicit move semantics generation)?

If so, is there an undocumented compiler switch like "Qoption,cpp,--alias_declaration"?