Re: [boost] [type_traits] fully qualified names

From: John Maddock (john_at_[hidden])
Date: 2005-03-11 06:42:55

> Always use a fully qualified name to refer to an integral constant
> expression.

Correct, but see below.

> However, it appears that the same compiler (BCB6) has problems if the
> '::' is left in.  For example...
>
>
> template <class T>
> struct Foo
> {
>  typedef typename ::boost::remove_reference< T >::type type;
>  typedef typename ::boost::add_reference<
>      typename ::boost::add_const< type >::type
>      >::type ref_to_const_type;
> };
>
> fails to compile.  Initially I thought it had something to do with
> typename (e.g., another BOOST_DEDUCED_TYPENAME) because, the first,
> simpler line compiles if I remove the "typename" keyword.

The thing is your typedef names a *type*, and *not* an integral constant 
expression, and as you have discovered, typename can't be followed by :: 
when using Borland.

Keep the typename and remove the :: when using types, but keep in in when 
refering to values.

Simple eh? (Just kidding).

John.