int main() {
        auto f = (bool = false) {};

        f();
        return 0;
}

I can't compile this code on
DMD32 D Compiler v2.062

On windows. It says to me:
Error: expected 1 function arguments, not 0

On linux it seems to work(http://ideone.com/fsKYWR).

On 04/28/2013 01:53 AM, Temtaime wrote:
> int main() {
>          auto f = (bool = false) {};
>
>          f();
>          return 0;
> }
>
> I can't compile this code on
> DMD32 D Compiler v2.062
>
> On windows. It says to me:
> Error: expected 1 function arguments, not 0
>
> On linux it seems to work(http://ideone.com/fsKYWR).

It is probably one of the known issues with default delegate parameters:

  http://d.puremagic.com/issues/show_bug.cgi?id=3866

Ali

Temtaime:

>         auto f = (bool = false) {};

I don't understand this syntax.

Bye,
bearophile

On 04/28/2013 09:14 AM, bearophile wrote:
> Temtaime:
>
>>         auto f = (bool = false) {};
>
> I don't understand this syntax.
>
> Bye,
> bearophile

The name of the parameter is omitted. Could have named it as 'p':

    auto f = (bool p = false) {};

Ali

Ali Çehreli:

> The name of the parameter is omitted. Could have named it as 'p':
>
>     auto f = (bool p = false) {};

OK. But is it syntactically allowed in D to omit the variable name when there is a default argument? I have never seen it before...

Bye,
bearophile

On Sunday, 28 April 2013 at 18:40:20 UTC, bearophile wrote:
> Ali Çehreli:
>
>> The name of the parameter is omitted. Could have named it as 'p':
>>
>>    auto f = (bool p = false) {};
>
> OK. But is it syntactically allowed in D to omit the variable name when there is a default argument? I have never seen it before...
>
> Bye,
> bearophile

That's because currently no variable name means _param_XXX,
moreover it can be accessed.

int dummy;

void foo(ref int = dummy)
{
	_param_0 = -1;
}

void main()
{
	int x;
	foo(x);
	assert(x is -1);
}