Is [ 0, 1, 2 ] an immutable array?

[Lars T. Kyllingstad]

Ali Cehreli wrote:
> Does the expression [ 0, 1, 2 ] form an immutable array? If so, is the assignment to a[0] undefined below? Is it trying to modify an immutable element?
> 
>     int[] a = [ 0, 1, 2 ];
>     a[0] = 42;
> 
> The reason for my thinking that [ 0, 1, 2] is an array is because it has the .dup property and this works too:
> 
>     int[] a = [ 0, 1, 2 ].dup;
> 
> Thank you,
> Ali
> 


Nope, it's an ordinary, mutable array. :) To create an immutable array 
you can do like this:

   // This is an immutable array of ints:
   immutable int[] a = [ 0, 1, 2 ];

   // This is an array of immutable ints:
   immutable(int)[] a = [ 0, 1, 2 ];

The .dup property simply creates a copy of the array, which can be 
useful whether the array is immutable or not.

(Note that there will be some changes in array syntax/semantics from the 
next version of DMD2. In particular, arrays of type T[] will be 
unresizable. Resizable arrays will have a new type, denoted T[new].)

-Lars