Readonly class members

[Hasan Aljudy]

Ever heard of "private"?

Georg Wrede wrote:
>> From time to time I wish that C++ would have a readonly specifier 
>> that  works like this:
>>
>> class Obj {
>>     void f() {
>>         int m_size = 10;  //ok
>>     }
>>
>>     readonly int m_size;
>> }
>>
>> void func() {
>>     Obj o = new Obj;
>>     int v;
>>
>>     v = o.m_size;  //ok
>>     o.m_size = 5;  //error
>> }
> 
> 
>> 'm_size' can be accessed inside 'Obj' as normal, but outside the class
>> the variable cannot be modified. Of course, I could provide a read
>> property (that is, a function in C++) for accessing 'm_size' (in
>> addition to a write property), but when it's not necessary, this way is
>> simplier (and a little bit faster, etc.).
>>
>> In D this, however, is not needed because you can use properties to wrap
>> member variables.
>> (Hopefully the properties will be extended to support the same methods
>> that can be applied to variables also... ;) ) 
> 
> 
> Hmm. IMHO, this would be very easy to implement in the compiler. It 
> would make class definitions clearer, and in many cases would lessen the 
> need to write code.
> 
> Just off-hand I can imagine quite a few situations where I'd use this.