The following compiles and crashes with DMD 2.063.
Should this be a compile time error?


class A
{
    int _var;

    void var(int i) @property
    {
        this.var = i;   // oops, crashes.
    }                   // should have been this._var

    int var() @property
    {
        return var;
    }
}

void main()
{
    auto a = new A();
    a.var = 3;
}

deed:

> Should this be a compile time error?

In general it's not easy for a D compiler to perform that kind of validation.

Bye,
bearophile

On Wednesday, 19 June 2013 at 11:33:43 UTC, deed wrote:
> The following compiles and crashes with DMD 2.063.
> Should this be a compile time error?
>
>
> class A
> {
>     int _var;
>

/* SNIP */

>     int var() @property
>     {
>         return var;
>     }

Isn't the problem in this property function?  (Shouldn't it return _var :o)

> /* SNIP */
>
>>    int var() @property
>>    {
>>        return var;
>>    }
>
> Isn't the problem in this property function?  (Shouldn't it return _var :o)

that's also an error. changing to _var gives same result though..

Am 19.06.2013 13:40, schrieb Iain Buclaw:
> On Wednesday, 19 June 2013 at 11:33:43 UTC, deed wrote:
>> The following compiles and crashes with DMD 2.063.
>> Should this be a compile time error?
>>
>>
>> class A
>> {
>>     int _var;
>>
>
> /* SNIP */
>
>>     int var() @property
>>     {
>>         return var;
>>     }
>
> Isn't the problem in this property function?  (Shouldn't it
> return _var :o)

that isn't the problem - D allows assignment to an read property - and there is no write property around, so it should be an compiletime error

i should compile only if the missing write property is available - or?

@property int var(int value) { return _var = value; }

On Wednesday, 19 June 2013 at 11:33:43 UTC, deed wrote:
> Should this be a compile time error?

Yes it should, in an ideal world. Expanding out the assign property, what we've got is:

void var(int i)
{
     var(i);   // endless recursion.
}

Linux segfaults on stack overflow, so that's your crash.

> that isn't the problem - D allows assignment to an read property - and
> there is no write property around, so it should be an compiletime error
>
> i should compile only if the missing write property is available - or?
>
> @property int var(int value) { return _var = value; }
>

sorry i've totaly lost seeing the write property :(