Dynamic Arrays & Class Properties

[Denis Koroskin]

On Fri, 29 Aug 2008 01:19:34 +0400, Jarrett Billingsley  
<kb3ctd2 at yahoo.com> wrote:

> "Denis Koroskin" <2korden at gmail.com> wrote in message
> news:op.ugl05wn1o7cclz at proton.creatstudio.intranet...
>> On Thu, 28 Aug 2008 22:22:44 +0400, Sergey Gromov  
>> <snake.scaly at gmail.com>
>> wrote:
>>
>>> Mason Green <mason.green at gmail.com> wrote:
>>>> Hi,
>>>>
>>>> Anyone know how to expose dynamic array elements via class properties?
>>>> I would like to do something this this:
>>>>
>>>> class Foo {
>>>>
>>>>     private int[] m_dummy;
>>>>
>>>>     this() {
>>>>         m_dummy ~= 19;
>>>>         m_dummy ~= 77;
>>>>     }
>>>>
>>>>     int dummy( ??????? ) {
>>>>         return m_dummy[x];
>>>>     }
>>>> }
>>>>
>>>> void main() {
>>>>     auto foo = new Foo();
>>>>     Cout(foo.dummty[0]);     // Print 19
>>>> }
>>>>
>>>> Any help would be much appreciated!  The question marks are where I'm
>>>> stuck....
>>>
>>> class Foo {
>>>     private int[] m_dummy;
>>>     const int dummy() {
>>>         return m_dummy;
>>>     }
>>> }
>>>
>>> I think this is better than tons of templates.
>>>
>>
>> First, it should be like this:
>>
>> class Foo {
>>     this()
>>     {
>>         m_dummy = new int[1];
>>         m_dummy[0] = 19;
>>     }
>>
>>     const(int)[] dummy() {
>>         return m_dummy;
>>     }
>>
>>     private int[] m_dummy;
>> }
>>
>> Second, that's D2 :)
>>
>> That's kinda strange, but unfortunately most of the discussion here is
>> about D1, not D2 :(
>> There is no const in D1:
>>
>> const int[] test = [0, 1, 2, 3];
>> test[0] = 2;
>>
>> writefln(test[0]); // prints 2
>
> On Windows.  I'd bet that'd give you a segfault on Linux.  Though it  
> doesn't
> change the fact that it's actually incorrect and that the compiler really
> *should* give an error for it.
>
>

There is also a final in D1:

final char[] test = "hello";
test.length = 4; // Error: cannot modify final variable 'test'
test = "world";  // Error: cannot modify final variable 'test'

but it doesn't work very well, too:
test[0] = '!'; // success

and everything compiles "fine" with -v1 switch (what does it do?):
final char[] test = "hello";
test.length = 4; // no error