in vs. const

[Sean Kelly]

dsimcha wrote:
> All the discussion about const on this NG lately has made me realize that I
> have no idea what the difference is between const and in, i.e. what is the
> difference between:
> 
> SomeType foo(const SomeType bar) and
> SomeType foo(in SomeType bar)

There's no difference between them.  The 'in' version just happens to be 
D1-compatible, and its meaning could be more easily changed over time if 
any tweaking is necessary (unlikely).