Arithmetic type emulator helper class for testcases.

[Paolo Carlini]

Hi,

> Attached is a patch with just a subset of the full patch. I
> moved the is_monotonic static member var and the "now()" static member
> function to chrono.cc. I tried to model it after mutex and condition_variable
> but linking anything against libstdc++.so gives two linker
> error's.

Ok, I'll have a look.

> Sorry for the formatting

Yes ;) This kind of "compression" we don't want:

+        duration& operator--() 
+        { --__r; return *this; }

Also, something you can fix immediately, without waiting for further feedbacks, essentially *all* your free functions, like all the operators, are very simple and should be marked inline.

Paolo.