[Patch] Second half of tr1/complex

[Paolo Carlini]

Howard Hinnant wrote:

>> (*) Is it even legal using the 'arg' name together with a using
>> namespace like this?!?
>
> <nod> It's legal.

I can trust you, but I want to understand in detail. Isn't true that
'arg' is a reserved name? Otherwise, if the user can use 'arg' in any
way, then do 'using ...arg', conflicts are always going to occur, one
way, or another.

Paolo.