Why is Exceptions c'tor this(immutable(char[]) instead of const(char[]) ?

[Steven Schveighoffer]

On Thu, 26 Aug 2010 16:24:57 -0400, Mathias Laurenz Baumann  
<anonym001 at supradigital.org> wrote:

> Okay, sounds reasonable.
>
> What about many of the phobos functions, like for example from std.regex:
>
> int find(string s, RegExp pattern);
>
> I mean, that function won't store anything, right?

This is where I normally agree with you ;)  From what I understand, there  
are quite a few phobos modules that need some TLC.

-Steve