const member function

[Baz via Digitalmars-d-learn]

On Saturday, 21 February 2015 at 07:31:19 UTC, rumbu wrote:
> On Saturday, 21 February 2015 at 07:01:12 UTC, Baz wrote:
>> ---
>> class S
>> {
>>    private SomeType cache;
>>
>>    public const(SomeType) SomeProp() @property
>>    {
>>       if (cache is null)
>>         cache = SomeExpensiveOperation();
>>       return cache;
>>    }
>> }
>> ---
>>
>> the result of the getter will be read-only
>
> My intention is not to have a read-only getter, I want to call 
> SomeProp on a const object:
>
> class S
> {
>     private int cache = -1;
>     private int SomeExpensiveOp() { return 12345; }
>
>     public @property const(int) SomeProp()
>     {
>         if (cache = -1)
>             cache = SomeExpensiveOp();
>         return cache;
>     }
> }
>
> unittest
> {
>     const(S) s = new S();
>     auto i = s.SomeProp;  //mutable method S.SomeProp is not 
> callable using a const object
> }

right, i have not carefully read the body of the Q. my bad.