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

[Mathias Laurenz Baumann]

Well, topic says it all. Why is the string parameter for the Exception  
class in object.di an immutable(char[])?

A const(char[]) works for both, immutable(char[]) types and char[] types.  
why this limitation?


--Marenz